Incorrect item sent and no replacement received

Bought an item and received incorrect item. Returned item and the incorrect item was delivered twice. The third time was advised account will be credited as they don’t have stock on hand yet item is still available online on their site. Was not even given option to get my money back but account was credited so I can use the credit on next purchase. What if I don’t ever want to buy from you again. Please sort out asap. I need the item I paid for.