money making scheme!!!!

MTN works in such a way that you feel ********** as a loyal customer of many years! After recharging my data bundles, they expire after just two days even without being used. Since when do they cap my bundles coz I've always had them last a whole month. I recharged with 300 data bundles on the 24th April and got an sms on the 25th April to say they will expire in two days. I've always recharged this way and have never received such an sms. I want what I paid for or at least a settlement balance to settle this contract and move to another service provider. And their pathetic call centre is useless!!!