dca and rights at the door?

A need for some guidance
A DCA PURCHASER  "may use force "..(to get into your home)..." because you have contracted with them" If a dca purchaser  with whom you have made an arrangement to pay a monthly repayment  should come to your  door because you will not agree to pay a higher amount  ( without first having made any  appointment to call on you  )  what rights  may you have to deal with this situation ?
Have heard that you can :

a. refuse  to talk to them and  on the grounds that:
They are neither  of or from   the authorities - so  they have  no power to demand that you must answer any of their questions ( no different in authority from say ,a window cleaner?)  nor made any appointment to call ?

b. take the following action :
1.Advise  that if they are unhappy with the payment amount ,the matter should be discussed  further in court, only ?
2.If they refuse to leave after being  asked to leave, state to them that (under THE CCA act 1974?)  ,they are  carrying out an act of harassment  and  with no appointment ,trespassing ?
5. Ring the police to have them removed if they continue to argue ,refuse to leave and cause  distress; the  harassment has then become a common assault and the trespass , an aggravated trespass?
any advice welcome on whether or not the above is correct ,please.

Hi bonnie,

Unless its court fine or an alledged debt to HMRC  then any debt collector has
no rights.

Just inform them that their implied rights of access are withdrawn.

Use this ,just need to fill in your address

To all it concern WARNING NOTICE  to anyone having business/visiting
NOTICE TO AGENT IS NOTICE TO PRINCIPAL AND NOTICE TO PRINCIPAL IS NOTICE TO AGENT APPLIES
NO TRESPASS
NOTICE REMOVAL OF IMPLIED RIGHT OF ACCESS
You are advised to read the following notice thoroughly and carefully. It is a lawful notice. It informs you. It means what it says.

I hereby give notice that the implied right of access to the property known as  and surrounding areas, has been removed, along with all associated property including, but not limited to, any private conveyance in respect of the following:

1) ANY employee, principal, agent, third party or representative or any other person acting on behalf of any CORPORATE BODY (i.e. Company) howsoever named and,

2) ANY POLICE OFFICER who is acting for the CORPORATE POLICE and NOT acting as expressed in the Oath of Office of all POLICE men and women, that is as Public Servants, upon your Oath of Office to serve "with fairness, integrity, diligence and impartiality, upholding fundamental human rights and according equal respect to all people; and that I will, to the best of my power, cause the peace to be kept and preserved and prevent all offences against people and property"

COMMON LAW JURISDICTION APPLIES EXCLUSIVELY

Please also take notice that this country is a Common Law jurisdiction and any transgression of this notice will be dealt with according to Common Law.
Any and all access to the above mentioned properties shall be by strict invitation only and shall be subject to terms and conditions, available by written request.

We do not have, and have never had, a contract. And any permission that you believe you may have from me is hereby withdrawn. If you believe that you have power of attorney to act on my behalf you are hereby fired, and any consent that you believe you may have, tacit or otherwise, is hereby withdrawn. If you feel so inclined as to enforce statutes as a consequence of this matter I will report your conduct to ALL relevant bodies and will pursue Proof of Claim in affidavit form, under your full commercial liability and under the penalty of perjury. You are deemed to have been served this notice with immediate effect. There will be a charge of £4,950.00 for any incursion what so ever.
In sincerity and honour, without ill-will, frivolity, or vexation
Without any admission of any liability whosoever, and with all Indefeasible Rights reserved.
Errors & Omissions Excepted.

Many thanks ,Daveiron. I came to this site some years back when i was in a "pickle" and you gave me some good advice then ,invaluable I would say.
things have moved on since then ,some for the good and unfortunately, some for the bad(health /employment etc.) My enquiry  above refers to a developing situation that is now a  potential issue  ; depends on new info and whether or not there`s also going to be a rational response from the other side  (like pigs might fly!)
Without doubting for one minute the value of the notice  you`ve kindly directed me to ,can you tell me if the "law" will generally  honour  their oath :do as it asks of them? A few  vids I've seen  show police being disparaging ,just standing by  aggressive locksmiths and thugs?

Just a few questions if you dont mind ,
What type of debt is it ?
Has it been to court ?
Are these bailiffs or debt collectors ?
any relevant info (nothing that will indentify you)