We just want a paid up letter

My husband owed woolworths and his account was handed over to a debt recovery company. After some time my husband settled to account ..2 years later they called him to say the account was not settled and the company that handled to account is no more working for Woolworths..we went to inquire because we were applying for a home loan they told us the amount is now even doubled and they have no record of the previous payment even though we have proof of payment. So my husband payed and settle the amount given at woolworths and got the proof of payment now they say we should have paid the money to another debt recovery company they hired and that company is the same company that said they gave back the account to woolworths and we must pay woolworths. Husband went back to get the paid up letter woolworths asked him to pay R180 so that he can get it..it's been now 6 mnths we still haven't gotten the paid up letter and still getting the run around. Please help us because we want to apply for a home and this issue is keeping us to do so