Reinstate Airtime

MTN service is pathetic and very unprofessional. I lost my phone in September and block both the phone and the Sim card . I have R340 worth of airtime ( not minutes) i normally get about R230 airtime every month . I call in a few days after I lost my phone to ask about my airtime and I was told all my airtime will be reinstated as soon as I do a sim swap . I did not do a sim swap immediately because I was waiting for insurance to replace my phone . Now they don't want to reinstate my airtime , I have spoken to different consultants and they are all unprofessional. One of the consultant by the name of Bianca , advised me she will escalate the matter to manager and get back to me , till this day not one has given me feedback instead I got an email that my query has been resolved but how if a manager must come back to me ?? I need my airtime because I have paid for it .