Cheated out of data and minutes

I have an MTN contract which has been for more than 5 years now unfortunately their service has deteriorated. Firstly I get minutes and data on a monthly basis, this month my data was not loaded and I logged a call and was promised within 24 hours it will be loaded. Nothing, I called again then they say it was loaded originally and on the new package I changed to on the 2nd December I only get YouTube data, I didn't ask for that. I ask if I can change back, they cant help. They will investigate if my data was loaded and get back to me. I have to wait another 24 hours. I have a topup plan so I buy airtime if I dont want to finish my minutes and use the airtime to buy rush hour. I tell them this week I've been buying rush hour to make calls yet it is deducting my minutes which are getting finished. So basically Im being charged twice - minutes and rush hour. It is not fair. I want my data and minutes back.