After 4 years, virgin claim we are in debt to them

After cancelling a virgin mobile account which we had to go through Hello Peter in order to do so, Virgin are now claiming that we owe R149 as well as any other legal expenses as a result of the debt. When we called and cancelled the account we asked the person on the phone if there was any other outstanding amount and they said no. I have been asking the to look in their phone records and they seem to avoid the topic and not handle the situation.<br> Its wrong that they are now claiming money from us when everything is settled and was settled 4 years ago.