Highly disappointed!!

I am so disappointed in mtn!! I have had problems with my mobile data for 5 months now, i sit with 43GB of data, and I cannot use it, and mtn just don’t pitch to sort it out! I pay for a service I can’t even use! Mtn store in Jeffreysbay told me it’s my iPhone that gives the problem, i have upgraded and still the problem persist! I have phone mtn call center, emailed them, still nothing! I will not recommend mtn to anyone!!