Airtime Disappeared

11 march 2015 i had a airtime balance of R400 , i tried making a call on the 12th march 2015 to my surprice i didnt have airtime. All the airtime i had disappeared only left with R13.00 which i can only make MTN to MTN calls.I called MTN 808 on 12 march 2015 20h23 i spoke to Lindi she told me she will escalate whick will take 4-24 hours. On the 13 march 2015 2h40 i called again spoke to Fred he told me it will take 7-14 working days until i told him i wont wait that long for this matter to be resolved, he escalated to team leader and they told me that they dont have access to the systen to reverse airtime only day shift staff have access however i should call on the 14 March 2015 Reference No. *** Airtime Missing R403.74.I called on the 14 march 2015 spoke to Thabo which also told me Fred gave me incorrect Information and that this matter will take 3-4 Working days, i told him to escalate to team lead he kept me waiting for more than 35 minute on the phone till i was cut off. i called again spoke to Tsholofelo she to me another turn around time of 7-14 working days, This is really a Very bad service which i pay for every month. I want MTN to reverve my airtime ASAP