Swim Swap done without my identity verification

please help On Friday the 5th i woke up with my phone without network saying emergency calls only , i dint know what was happening i assumed maybe i had network issues ,i stayed the whole day and Saturday . at around on saturday 14:30 i went to MTN store to enquire , i was told that my phone number did a swim swap and there was about R170 .00 xtra airtime borrowed , i was told that i cannot recover . i did not do any swim swap or verify for that but now i have to pay for something i dnt know , when you do swim swap normally you are required to provide identity and in this case someone did swim swap without identity and it was sucessfull .