no answers to enquire

I am an mtn contract holder since 2005, since last year problems with this network have been piling up. wen I try getting help from their contact centre 808 they have no answers and always logging queries without providing feedback. lately I purchase data bundles every day and 30 mb a day and I only use them on whatsapp. I don't even download images sent to me as it takes all the bundles. I called the contact centre again today as airtime disappeared and I have data bundles, they couldn't see anything on their systems and said I should wait for my statement to close on the 10th of next month. so my question to mtn is that I should wait until they decide to tell me where the airtime is or I should end the contract of 10 years. in all tthese years I have never missed a payment and everytime I go for an upgrade they always have issues<br> I want my airtime and the data you guys chaw