Disgusted customer

I'm am so disgusted by mtn I have a contract with them my data gets in every month on the 12 yesterday was the 26 but my 20gb data just finished and normally it finishes exactly on the 11th or the 12th or it get the other data without it being finished now I call them the whole day asking them wat is happening y my 20gb data is finished within a week they say it's Instagram which I don't have an account of it they say maybe my wifi is hacked I asked them to prove it they can't nd they say I streamed videos which I don't do nd don't even know how to so they gave me no solution I want to cancel my contracts with them I since had contracts with them since 2013 they do not know how to treat customers they put me through a Manger who couldn't also assist me his name is Mr Lindokuhle Gcwensa I don't want anything to do with mtn right now I'm disgusted with their services