I cannot give specifics yet because it is an ongoing dispute, but I have a problem where a registrar sold me a domain then a few hours later took it from my account saying they charged me wrong and I could buy it later for a much higher price. I have receipts and copies of the whois from the sale. What do you think?
You would need to post a lot more details about the transaction, including the TOS of the purchase. Unless you are talking about tens of thousands of dollars it's not going to be worth it to take legal action.
Sure you can. The U.S. is the best example of anyone suing for anything. Of course, winning and enforcing your win are different stories altogether.
It might be cheaper just to pay the higher fee. Was this an existing domain purchased through a market place? If so, and it was mistake, it would be hard to force them to transfer it away from the current owner.
Who's the registrar, out of curiosity? If it's Network Solutions, good luck since their contract has been upheld at least once in 2003 AFAIK. Just be aware, though, that you don't really get to say which terms apply to you and which don't. Of course, only the judge will ultimately say if the terms of that contract are enforceable or not.
Same thing happened to me a while back, but I didn't fight it. I would be interested to see what can be done about this issue.