Extremely bad service from PEP.

We bought a telkom Sim card from Pep Vereeniging under number ***. My son's phone got lost and now Telkom refuses to help blacklist the devices on the basis that the sim card was not ricard in my name nor my son's name. Pep sold us a pre ricard sim card belonging to someone else( which we do have the name of). We are now struggling to blacklist the phone due to the failure of Pep to follow the right process to ricah the phone under our details