Boardwalk Buy shipped me item not as described, won't refund the total cost of item + shipping + return shipping Internet

I purchased a swimsuit from Boardwalk Buy that was advertised as being of colors navy and red, and was listed with sizing measurement information. I measured myself, and ordered the sizing category that my measurements fit into: Large.

When I received the swimsuit, it was very much blue and pink, and additionally was far too small to fit me. I e-mailed Boardwalk Buy immediately with the details of my issue and requested a full refund for the cost of the item + shipping. ($22.30 total--$18.80 for the item, $3.50 for the shipping) I also said that I would be happy to send the item back to them if they would send me pre-paid shipping. They replied to me that they would not pay for the return shipping, and that they would also not refund my money unless I shipped the item back to them (additional cost to me: $3.21) and provided them with the tracking number of the item.

I did provide them with the tracking number for the return shipping, and again requested that they refund me the total amount, now $25.51 with the return shipping. I told them I was happy to provide an image of my receipt for the shipping. I do not want to pay for the shipping of an item that was falsely advertised both in color and in sizing--especially when they had specific measurements in addition to the generic S/M/L sizing convention. They have refunded me the price of the item, but not the cost of shipping it to me the first time, nor the cost of me shipping it back to them, which they demanded of me else they would not refund my purchase.

I am now at a loss of $6.71, with nothing to show for it but a lot of headache. They offered my store credit for the amount of the return shipping, but after having a terrible experience with their product and their customer service, I am not going to buy from them again. I told them as much, and that I just wanted the money refunded to me. They have refused.

That is not acceptable.

It is not acceptable to sell me a product that it not in reality how it was advertised on your website, and then, when I wrote to you for a refund, not refund me the cost of shipping as well.
It is not acceptable to require me to ship said product back to you [else you would not process my refund at all] and then not cover the cost of return shipping.
It is not acceptable that I (taking into account the $18.80 you have partially refunded me) have still paid $6.71 and have gained nothing from my money spent while you have your product back that you can turn around and sell again.
It is not acceptable that you boast good customer service while in reality you have not provided that to me.

I have contacted the BBB about this company.