Inconvenienced by MTN glitches!!!

I have two MTN cellular numbers. For the past few weeks everytime I'm on the Internet, [URL Removed] pops up, informs me that I have no data or airtime left, and prevents me from accessing any further pages. When I check my balance, it shows that I do have data and airtime, but I can't access the Internet, thanks to MTN. My airtime also mysteriously dissapears, within a day of recharging, without any phone calls or sms's being sent by me. This is absolutely unacceptable, a MAJOR inconvenience and INFURIATING!!!!!!