MTN has *****ed me again

I don't know where to start... I bought 2GB of data like I normally do for the month on 27/04/2016 but I still had 600MB left of my previous bundle that was set to expire on 29/04/2016. Normally, there would be no problem because the data depletes from the bundle set to expire soon but on this occasion, it started taking from my new bundle instead of the old bundle so on 27/04/2016 I rang their call centre and the first person made me switch off my phone and told me that it will be sorted within 10 minutes after he reset my number on the network. After 30 minutes, I called them because it wasn't sorted so I called again and spoke to a lady who didn't know what I was talking about and after I explained it 7 times, she told me that she can't fix it and will transfer me to Technical Support.... While holding for "Technical Support", I suddenly heard a voice prompt: "The number you have dialled is incorrect, please check the number and dial again... beep...beep...beep... and my call got disconnected... I didn't even dial anyone!!! I was furious and called again after an hour so this guy made sense of the situation and told me that he will escalate it to his supervisor and give me a call back within an hour or so..... I'm still waiting after 3 days!!! I love some of MTN products but if this is the manner I get served, then I am thinking that I should move and port my number out to another provider...