Contracted Airtime not supp****

I was on holiday in Abu Dhabi from 18/12/2015- 16/1/2016 and made no phone calls during this period of time.I only used it for what's app with WIFI ,only when at our place of accommodation .<br> I am on a mychoice100 Topup contract which means every month end I get topped up with R100 airtime,10mb data and 25sms's.<br> <br> When I checked my balance on the 11/1 whilst still in Abu Dhabi ,I was shocked to see that my airtime balance was only R11.50 .My balance on sms's and data was correct as per the contract.<br> <br> HOW CAN THIS BE POSSIBLE when THIS PHONE WAS NOT SET FOR ROAMING?????? <br> <br> Or could it be because the phone was not set for roaming it did'nt technically accept the airtime loaded.?<br> Please help cause MTN customer service is hopeless and don't seem to understand or don't want to .<br>