Incorrect handover of my account to 3rd party when I do not owe anything

I gave Supersonic a notice in in June to terminate my contract on the last day of July 2025. I reminded them again before the end of July that I will be moving to another unit in the Complex so the services must be terminated of which they agreed. I informed them as I moved out to check if they terminated the services as I moved out. They promised to terminate the services.

A few weeks down the line I received phone messages that I have an outstanding amount. I phoned and explained and the agent followed up on the matter and later phoned me that my account/ services seems to be active on their side but he will follow up. He later contacted me to inform me that the issue has been resolved and my account was credited as the mistake was on their side.

I conducted my account very well while being their customer and I was satisfied with their WiFi.

Now I receive notifications from the 3rd party that my account has been handed over to them. Can someone at Supersonic please respond to this as it is wrong in many ways.