Pathetic Customer service and finance team service

I pay my invoices regularly. In January 2024 they changed my account number but I was still using my old account number as reference for all payments couple of months later I geta call from a debt collector company that I owe super sonic. I logged a ticket with supersonic and shared my proof of payments, after a few days they closed the ticket and January invoice was still showing as not paid. The debt collector guys call me everyday because of someone in finance team does not do their job. I have spoken to supersonic multiple times but no result. to ad it if you contact them using their whats app line then be ready to wait for couple of hours before they reply and i you miss their reply then you need start over again. I cant have my credit history looking bad because of their team not doing their job properly. I will have to eventually change my service provider