Review You ignore your customers why?

I owed topics some money which was paid in full by former employer.i asked topics in july 2018 if all was now ok and they did not respond.Come august 2019 i ask them again and they where so quick to tell me i owed them $144. Upon requsting an explanation of where that money was coming from they started to ignore me. I have been sending them emails almost on a daily basis requesting for a statement and they dont respond. Topics i need you to respond to my emails and tell me where the $144 is coming from. you were so quick to tell me how much i owed but you cannot explain how that money came to be.