SEVEN DAYS FOR REFUND FROM MTN WHEN BYING CASH ITEMS

We Bought a Router/modum Cash at MTN Eshowe, we do not have coverage at the house, we spoke to Sibosiso the store Manager and was told that we should bring it back the next day for refund there will be somebody there to assist us, we arrived at the store there are nobody trained to do refund, then I was told apparently it takes SEVEN DAYS FOR A REFUND??????? what a load of nonsense