Disgusting behaviour not dealing with the Debt Review company

I am absolutely appalled by the service from this company. I have been handed over due to non payment on an account - 100% understandable. However, as I am currently under Debt Review due to my financial situation, they are not even allowed to contact me anymore and have to speak to the Debt counselling company directly but they refuse to do so. I am getting daily calls (after me requesting multiple times that I cannot answer my phone during the week due to my job). They come with a story that, I have to personally send them my Debt Review forms (none of the others requested that) but I send it to them either way via WhatsApp over a week ago where I received confirmation of receipt. However, I still get calls saying they didn’t receive it. I am absolutely disgusted that they seem to not do their jobs of allocating forms sent and now continue to harass me. Oh but as the lady on the phone states - I shouldn’t be getting upset and ‘raise my voice’. I will take this further with RCS (whom the account is with) as someone is not doing what they are supposed to and by Law when an individual goes under Debt Review they have to correspond with a company.