Wow, I need my money back.

I bought a laptop online,I received it however didn't receive an invoice I tries to get the invoice for close to a week cause I wanted to return it , after the Hassel.i returned the laptop at the shop in Bloemfontein and to this day almost 2 months I haven't received a refund but they took back the laptop. I haven't received any communication and I needed the laptop to finish writing my thesis.