Paid up account is with MBD

Good day I have settled my account at Jet last year during lock down, i paid according to the amount they state on the sms at usave if or pick n pay. Now the accout is with MBD. They have been calling me i told them i have settled no no one bothered to check why i am saying its paid up. I went to carlton center they said their system cant see the latest payment i have made. Please assist