Upgrade reversal

I took cellphones from Vasco connect and I returned them because I was not satisfied with it, I tried to call them up until today, they have not reversed my upgrade, mind you I took the contract mo the end of March we are approaching December on top of that they took me to collections Attorneys because they want me to pay for something that I don't have they even closed my MTN number and also MTN is not doing anything about it, I wrote endless emails to Vasco connect and MTN still no response