PAY FOR GOODS NOT DELIVERED

i placed an order on Boardmans website for cannisters and coffee mugs. The full amount was taken off my credit card. One week later they contacted me and indicated that they could only supply the cannisters as they were out of stock on the coffee mugs. The Ronald indicated that they would credit my credit card with the amount. He also confirmed that they would re-imburse me for the delivery fee as well. 3 days later the amount was still not credited back to my credit card. I contacted them again and Ronald confirmed that the amount would be credited back to my credit card the same day. Now 3 days later (one week later in total) this amount has still not be credited back to my credit card. This is really bad service and I will never buy and pay for anything on Boardmans website if this is the stance they are taking. It comes down to ***** retaining amounts that are not due to them.