A business is not refunding the full amount? Just the amount without taxes?

I recently put money on a calling card so someone in jail could call me. She was released the day I put the funds on so I called for a refund. How it works is you put $20 dollars on your account and that gets you five fifteen minute phone calls. They also charge you a processing fee of $2.00 and taxes. A total of $28.43 was charged to my card. When I called for the refund the representative said that she could only refund the $20 that shows on my account and that they have a $2.99 refund fee. I asked her what about the taxes you charged me and she had no clue what I was talking about she said it only shows $20 on your account and that is all she is authorized to refund that I would just have to wait to see what is accredited back to my card. Can they legally do this? Are they not making a profit off of the taxes I paid?