No service on tablet which was delivered cracked

Firstly, please note that this is a tablet, not a cell phone which means that I will not answer a call to my tablet.In February I was offered a tablet for R89 a month. I checked and double checked the amount. It was R89 pm. I pay R91.66 because apparently I need caller ID on a tablet. Regardless of the numerous times I have tried to cancel this. When I received the tablet the screen was cracked. I tried calling Altech but they were undergoing some issues and couldn't take my call. The issues being the person in the call centre, putting the phone down. Which happened again today! YOU HAVE MY DAMN PHONE NUMBER? IS IT SO HARD TO HAVE SOME SEMBLANCE OF MANNERS AND CALL BACK IF IT TRULY WAS AN ACCIDENT? I am not rude on the phone. Never have been. I sent an email saying the the screen was cracked (day 2 of receiving the tablet) I received an email back one month later saying it was not within the 5 days of receiving the tablet therefore it was my problem. Since February I have tried literally everything. I have not been able to use my tablet, apart from about one month, unless I am in a wifi zone. This can be verified from my data usage. I pay my bill every month!