Sounds like the potty has become a control item for your daughter (for what ever reason). If I were in your position as the mom I would completely give up trying for a couple weeks. Don't mention the potty, don't put her on it, don't ask her about it...nothing. Then the power struggle ends because there just is no option to control it.
After a good while start making it fun...show videos and books about the potty, don't let it become a control factor again so read her cues and see if she'll sit on it on her own free will. No pressure, no stress, no negative associations. If she is only 2 then I don't think there is a need to force it. If she were 4yrs old and doing this then a hard approach would be fine but she's young enough to just take a break.
Start fresh and hopefully she'll just roll with it. If she is using it at daycare sometimes then just let the daycare do what ever they are doing...she can watch the others and use it when she does. Let daycare know what you are going to try to do and why. So they can report to you that she is using it but don't mention anything to your daughter about her use at daycare.