no service

My name is yang Sunday i bought R15.00 airtime using ussd *130*321# for my cell phone {083} 4930 497 and when i checked my balance the error said system unavailable try again after 15 minutes, i waited the whole day and Monday i called the call centre they promised to credit my money back after 48 hrs ...i waited until today when i call back the lady by the name of vekash told me i must go to the bank and get a statement and fax it to menzi ***.....why must i fax the bank statement for R15.00? Now i need to go to the bank for what?...I'm taken for a fool here,,,a fax is R8.00 a page and taxi is R30.00,,i need my airtime or else!!!