Online order gone wrong

It's an online order with Cherry Melon for 1x dress with belt and 1x pair of pants. My ordered was delivered as scheduled but without the belt. I emailed Cherry Melon (the have no number on their website) asking if I could exchange the pants for a bigger size and for delivery of the belt. I was then informed by a try abrupt email that I would have to pay to courier the pants back to them and then they can exchange it. No where in their shipping policy is this mentioned. The price of the pants is not worth it if I have to pay for delivery and courier fees to exchange it. I then started enquiring about my belt. I have since received no feedback and response to my emails. I shop online weekly and I have never ever experienced this before. I paid for goods. I did not receive everything and now I'm being ignored. I don't recommend you shop online with them.