What else do I have to do to get my airtime?????

I've been with MTN for years now and have never experienced an issue like this. I am so disappointed and I am seriously considering changing networks once my contract ends in July. I have 2 contracts with MTN, both on top-up and both receive airtime on the 27th of each month. However, on 27 April only one of my numbers received it's R110 airtime and I still haven't received the R110 airtime and 100MB data for the other number almost 3 weeks later (and my next lot of airtime is almost due again). I have called, e-mailed, tweeted... all of which has resulted in, well, nothing! The issue just gets escalated each time and then I receive an sms to say it's been resolved, but it hasn't. I then have to call in after receiving the SMS only to find out that it needs to be escalated to another department. I am tired now.