Returned incorrectly supp**** part with no refund

I recently purchased number plate holders for my honda s2000. Honda umhlanga supp**** me the wrong set, despite having seen the car in question. I returned the part 5 days later and was told that they don't do cash refunds, they will do an eft into my account and it will reflect in two days. Since then I am still waiting. I've called the dealership 3 times and always the response is they will get back to me.