Data removed from my phone

I have renewed my account recently and ever since have been experiencing problems with my account. mtn offered 3 months x 10 GB but for 2 months they have removed the amount including the 2 GB which I pay for in my package deal resulting in having to purchase data all the time. I have reported the matter in last week when data was removed and have since had to call in every day for the outcome which they say is resolved but they still have not replaced any data. I did not ask for the 10 MB which they keep removing including my 2 GB which I'm am requesting to be returned .