MTN refuses to deal with incorrect billing

Since 2014, MTN has overcharged me for my data. It has not yet been resolved. Access to my online account is randomly taken away, and then I cannot even get access to my own statements. At times, when I do have access, my account details (billing, statements) are not available. No explanation or assistance have been offered regarding this.<br> <br> In my opinion, when MTN sends me an email, but refuses to confirm any of my issues, provide me with information, or offer a resolution, they have not \responded"or dealt with my query. <br> <br> My reality is still that it is too expensive to use MTN's \""free\"" 1GB of data"