It doesn't really depend so much on the payment amount, but rather how much you are paying in interest.

I am making the assumption the CC debt is high-interest debt, so that needs to be paid off first.

The REAL PROBLEM is how the heck are you getting a $15,000 tax refund. You need to really figure this out. You should be as close to $0.00 refund as possible. Otherwise, you're just giving the government money to hold interest free, while it loses value to inflation.