Unhappy client

My homechoice account was handed over to MBD without understanding why that happened in the first place because there was an arrangement in place. I then continued paying my account and then I eventually settled it. I called Homechoice requesting the settlement balance of which I then paid it. Then next thing I received an outstanding balance from MBD saying I still need to settle my Homechoice account, I explained to them that I had already settled my account with Homechoice but then they said Homechoice handed my Acc over to them so once I have settled the Acc with them only then will my Acc be settled. I then paid them and they sent me a paid up letter. Now I am still receiving statements that I am still owing Homechoice. Exactly who can update my Acc because now I am being sent from post to pillar.