Bad customer service

My account was handed over due to me not paying on time, that I understand. So they started deducting from account per month until covid happened and I couldn't carry on with the debit orders as I had no income but I made I pay off the balance owed to homechoice. Now that I have finish paying them I can't get a paid up letter homechoice tells me I must call the company they handed me over to for the letter, I called that company now they say I should pay again so that they can give me the letter. I mean why must I pay again if I already paid the full balance of what I owe? I don't have a contract with that company, homechoice does so why can't I just get my paid up lette? I'm so furious right now. Hello Peter please assist with this.