Account Sent for CANCELLED Service

DAY LIGHT ******* ONCE AGAIN...I cancelled my Telkom account on 23rd March 2020 - SMS proof received. Last month I assumed I was paying the final account, to my surprise I received yet another account today!!!! What is happening here? Are the records not being updated? I should actually be getting a reimbur*****t for the ******** charges on my account for additional services which I DID NOT request. These charges ran for 4 months!