I just want my laptop I don't wanna fight

I took my laptop in for repairs at the Westgate branch and they gave me back a wrong laptop. When I took it back to the store the customer service consultant tried to convince me that the old laptop they had given me was mine so after an hour of convincing them that the laptop wasn't mine they finally saw I was right and took the laptop then told me they would call me on Monday since it was a Saturday and their IT people don't work on weekends. I understood that but now it's been three weeks no call no communication whatsoever mind you my Jan/Feb exams are right around the corner and I have nothing to study with or check my school emails on. I swear I'm never buying anything from this store again. But first return my laptop hifi corp it's not funny anymore