well first off... i never expected your voice to be like that. 0.0... your voice is nice. ^-^
well this seems to be an internal problem... te detto that te just got te computer fixed... well if te didn't drop it o anything then it must have been a problem that stems from the repairman... he must have done something that lead to this (aka he messed something up)... te might have to take it back but te should plead your case that it was a issue that was caused da Their employees... see if ya can get a free repair.
The screen itself is damaged da the looks of it. I think te should take it to an expert to check it over though. Try restarting the laptop. I don't think te can fix that. te probably have to get a new screen.