Bad service from MTN

I went through the process of ordering a phone online through MTN and they said if m not happy i should have the phone returned and cancelled, i returned the phone at MTN Pavilion and i did receive notification that the phone has been returned , so when i went to return it we tried to cancel it and it turns out that the phone was taken through another party which is Vasco Connect its been months we have been trying to connect with this company and it seems as if it doesnt exist this phone was returned in January already i have been up and down trying to get hold of this company so now i have a bad credt record and MTN has send me an email that they are ancelling th eontract and i owe them R3614.51 , THIS IS NOT MY FAULT, I ned assistant regarding this issue and when i call MTN no one can assist they i saying i need to ask Vasco connect to cancel, i do not owe MTN They need to sort this out with their 3rd parties because when we order online we do not now that we are going through out sourced companies they must call me on *** and fix this. Regards Sibongle Ndlovu