Hifi corporation

Hallo peter i bought a laptop for my daughter at Hi-fi Corporation in fleurdale in Bloemfotein on the 5 October and returned it back unused becaused she said is not the one she is looking for and they took my details and bank details said they will deposit back my money within 7 days but to date is still not paid back but they took their laptop is with them. Is Exams time my daughter urgently need a new laptop i wonder how can a big shop like that fail to refund R4999.00 please help me.