Carers Allowance consent policy - implict and written consent

Hi
We have lodged an MR for a client signed by client & us and with their cosent attached. The MR was about a decision that client not entitled to CA for a past period and has been overpaid.,  Client now received letter from CA saying because there has been a change of circumstances we looked again at your entitlement and decided that you are still entitled to benefit, without mentioning anything about the past periods of non-entitlement.
Tried calling CA today to find out what this is supposed to mean and what they are doing with the MR.
The call handler reluctantly went through Implicit consent, but said that all they could tell is that the MR had been logged on 11 January, and that they could not tell whether the MR is being processed or not or whether the letter dated 12 1 23 she received was supposed to be the response to the MR.  They said regardless of whether there is a written consent attached to the MR, they cannot provide any information over the phone unless the customer is present at the phone call.
Does anyone know whether this is actually CA policy not to communicate with 3rd party adviser directly at all, or whether the call handlerr misunderstood CA policy?

Suspect you’re looking at three things:

1 - talking to an outsourced call centre worker. Access to relevant systems is often intermittent. Training on where to find stuff when access does work appears to be very poor indeed. Best tactic remains to end the call and start again. Eventually you usually get sense.

2 - the info. over the phone stuff is nonsense. There is clear national guidance but large parts of DWP related satellites continue to act as though it never existed and thus there is only explicit consent.

3 - some call handlers are handling multiple types of call or have worked with UC. They believe the UC approach is the only one which exists.

Thanks for your reply Mike.  i think poiint 1 definitely played big role, as the person I spoke to was not familiar with the abbreviation MR. 
Is this the guidance you were referring to?  https://www.gov.uk/government/publications/working-with-representatives-guidance-for-dwp-staff/working-with-representatives-guidance-for-dwp-staff

Yup. That’s the one.

Important to remember that it is a figment of our imaginations and we are absolutely not being gaslit.