What's wrong with my MacBook? It's flickering and beeps.

I bought my MacBook Pro 13" in October 2012. It worked fine and then on December 25 I was using it and a rainbow on vertical stripes started flickering and took over the screen so I had to hold down the power button and shut it down. I took it to the Genius Bar and she did nothing for me. About a month ago the screen started to flicker and was completely distorted. I took it in and they sent it to Austin where they reset the RAM. I got it back and yesterday I pressed the power button and the screen stayed black and it beeped three times then paused, beeped three times, paused, and continued in this pattern. And later last night I tried to turn it on again and it turned on but after about five minutes it flickered and the screen was completely distorted. So I forced shut down. The same thing happened again this morning with it working for about 5 minutes then distorting. This is annoying because I've taken it in twice and it continuously have the same problem. The only thing I have downloaded is Google Chrome. Before they sent it in and reset the RAM and to factory version I had Sims 3 on it but when I got it back Sims 3 wasn't on it because I was reset to factory settings, so Sims couldn't be causing it.