Item refund

I ordered a pool cue rack and they delivered the incorrect item. I logged a return and they collected. Received an email stating that the item is not longer available and that I have been credited. When checking the website there is still 1 available. They credited me for the amount of the item but never credited me for the delivery that I paid. This is the 2nd time they doing something like this. They mess up the order but dont refund the delivery fee that you paid. What a rip-off.