MTN Data contract *******

i took up a data bundle contract with mtn during a black Friday special for 30 gig a month . over the last few months they have not been loading the full data onto my sim card but have been debiting my account for the full contract value . when I queried this with customer care the first consultant I spoke to confirmed that the full value was not been loaded every month and they will investigate and get back to me . A month later there was no word from them and the same thing happened . I called customer care again and this time was told a different story that my contact was for a lower data bundle . the consultant asked me to e mail my contact which I did not have , so I contact the branch at Richards bay where I took out the contact and they could not help me because apparently all contracts are archived and they cannot get access to it . I then referred my query to the branch were I originally took out the contact , who registered my query . few weeks later I went in to find out on the progress and was told it is still under investigation , this was over a month ago and I still have no feed back . in the mean time im paying for something I don't have and incurring additional cost to buy data that I should have had . when tried to stop the debit order , I was told I could not stop it on the data bundle account because my cell phone and data bundle goes off the same account ( no issues with cell phone contact ).

have been paying the full value since 2017 Nov but since July 2018 have not been receiving the full data bundle .