DCS should be DCA debt collection agency

Hello all, need a bit of info here hope someone can help. I've owed the bank some money for over a year now firstly i tried to resolve matter with them but they started adding charge after charge and wouldn't reply to my letters. then they get Lowell finance involved who sent me a rather strongly worded letter with various comments typed in bold, sure you know the one's, i was angry and sent them a CCA request and a pound, nothing back not even my fee. sure enough then Moorcroft got involved (don't like this firm full stop) so i did same again, they tried to say they felt the matter didn't fall under CCA request. so after a long laugh i wrote to them again with a CCA request and that went the same as Lowell, no response no returned fee. now it's iQor who is on my case together with GPB solicitors. i have sent them both a CCA request and just today resent with there duties highlighted (after they sent me printed statements of the account) and again ask them to provide a signed copy of the credit agreement . anyway getting to the point! surely it is wrong for me to have three companies chase me for this money and all three fail to provide a credit agreement? are they allowed to pass on the debt when the first request with the first DCS has not been fulfilled?. if they cannot fulfill my request what will happen and what should i do? whilst i wait for your help i'm gonna send a letter to Lowell and my best friends Moorcroft as they owe ME money thank you.