Woolworths Account paid in full but I’m still blacklisted

I paid the account in full in July 2019 at that time I was blacklisted with an amount of R10 100, I forwarded proof of payment to TransUnion and my name was cleared from credit bureau in July 2019 . I discovered that I was blacklisted again by MBD debt collectors with an amount of R7496, I called Woolworths wanted to know why I was blacklisted again because my account was paid in full and they confirmed that the account was paid in full. Woolworths also sent me the proof but MBD told me that I was supposed to pay that amount direct to them but they instructed me to pay an amount R350 since 2015 to 2019 direct to Woolworths which I did. MBD did not provide me with their own banking details , they told me after I settled the account with Woolworths and Woolworths was supposed to inform them that the account was paid in full and I even sent the the proof of payment . Please assist me with this problem I can’t pay the account in full and be blacklisted by MBD. I was blacklisted by R10 100 which I paid in full so I don’t understand why I’m blacklisted again.