data bundle warning notification stopped

Hi<br> <br> I've been a loyal customer with MTN for over the past 10 years. In Oct 2014 I got a new upgraded contract, I get 500mb data a month. Since I've paid R650 per month and I have never exceeded this bill.<br> <br> I always used to get SMS notifications (which according to my invoice I get as a monthly service) indicating I am half way through my reoccurring data bundle. I would then know to cut down, or be aware. Since April I have not received this SMs notification, therefor I believed I was well within my data bundle usage.<br> <br> My last August bill, somehow I racked up 2GB worth of data, which amounted to a whopping R1300 just on the data alone. Considering MTN did not keep to their agreement and send me the necessary sms to highlight (as they used to and are meant to) I have used up half my monthly data, I don't believe I should pay this additional amount. Please MTN can you assist me with this query and get this amount for the data fee waived. I believe I am not the only one who did not receive this SMS. I have been a loyal customer with MTN for such a long time I feel this is a fair and just request.<br> <br> Thank you