DATA *****ING

I have been a loyal client of MTN for over 5 years now and I seem to have unending problems with the data. I am self employed and rely heavily on the data to make a living. On many occasions the data is slow or there is no coverage, I have also noticed data getting finished very quickly. I tried to call on several occasions but their call volumes are too high and my call gets dropped. Today I plug in my 3G and Im supposed to have about 2gigs and after about an hour of use it says my data has reached its half way limit. i have not downloaded anything, the same thing happened with my phone. It seems so strange . . . is this a just to get you to buy more airtime. I have also noticed that at night the data streams very slowly there is no HSPA or WCDMA why??? I can do any downloading and this supposed to be free ....GIMICK !!!! big companies like this are just filling their pockets and giving us a raw deal its outrageous