Broken Tablet

I bought a tablet on the 26 th Dec 2014. I tried to go on the play store appand it didn't work. I. took it back on the 7th of Feb 2015 so matrix could help me. They did. But they had to reboot it as the program wasn't installed properly. So I went home. Sunday when I inserted my simcard, it said no sim detected. I took it back that same day the 8th of Feb. I was told that the plates inside could be bent. They took it and had it for 2 weeks and when I phoned them they said that the warranty was void because I broke the sim card slots. only inserted a sim card into it for the fisrt time that friday the 6th Feb and it went in smoothly. Now they say the simcard bent one side and the other sim card slot is broken!!! I never broke the tablet as I NEVER inserted and took it out like ten times. And how can it break so easily if it was new?? My friends got a tablet and she is literally inserting and taking out the sim every day like a dozen times and I only inserted mine once!!! The tablet was a dud from the start. tablet is supposed to be under warranty as I only have it for almost 2 months!! Pls help