waiting 2 weeks for a refund

I purchased a rather expensive iPhone X cover on the 14th of December 2017. I returned it the following day, according to the sales person they can't do cash refunds in store and took my banking details for the money to be transferred to my bank account on Monday 18 December. I went back to the store Tuesday morning to find out about the refund, they assured me that it would be paid into my account by this morning (Friday 22 December). Still nothing! Which means I will have to go to the store once again after the public holidays. I think it is ridiculous that I have top wait 2 weeks for a refund! I paid cash, and returned the products unopened within 24 hours. really really BAD service. Will never buy from them again.