Both of my USB ports are not working

My macbook pro had some problems with the keyboard earlier, and I went to the apple store to get the replaced before I went back to school. But after the repair, one of my USB ports stopped working and recently the second one stopped working. I brought it again to the apple store a few days ago and they tested out my macbook, saying that both ports are powering the USB but are not doing anything else, therefore the USB ports basically don't work. They said that it was a problem with the logic board and to get it replaced I would have to pay $500, which I think is ridiculous seeing that it was half the amount I had paid for my macbook in the first place. I was wondering if anyone know how to solve this problem? I tried reseting the SMC as well as PRAM reset but none of those options worked. Would I have to replace the logicboard or at least clean it?

Please help! Thanks!