Q: do u have to refund if theres no counters
A: If there are no counters, you will lose your TC if you bet in the wrong guy. if you win, you'll just get the TC back. at least it was like that when i last joined a bet room, but since it's been some time, my information may be outdated.
Q: and also are you allowed to change the bet frames when your about to beat someone, and bet?
A: Not sure if it's possible, but if it is, it would be extremely stupid to do so, so don't, unless you want everyone calling you an asshole.