Absolutely disappointed, my payments not allocated and cannot be tracked

Im still in utter shock. I paid through Debt review my Woolworths account from 2016 to 2019 and in my statement it said that it was paid up. I just found out from Nimble that after years of paying, Woolworths withdrew the account and wrote the balance of R5700.54 off but I cannot get my Paid up letter because they cannot track my account. The agent advised me to pay off the initial outstanding amount, she'll give me a discount because they cannot track my payments. Imagine paying twice because the company cannot track my payments? Now, Im not getting my clearance letter due to this. It is shocking to be ****** by such a big group.