You paid them $50 for a year. If they want to pro-rate it, they take the percentage used from that. What they charge monthly is irrelevant. You didn't perchase a monthly package. You didn't set the prices up, you bought a product. The fact that they have a different price for another product doesn't affect a refund on the product you purchased.
This is just bad business. They appear to be beating around the bush to short change you. I wouldn't have it. :evil:
-Tanner