My question is if player A raises can player B take his/her bet back or is he/her committed to the call but can either call the raise or fold losing thier initial call?
I apologise I mean there is a bet and player A is to act.
Once A has indicated that they have been missed, it is at this point that all play should be stopped and taken back to the missed player. It should also be explained to the missed player (In this case A) before they are given their options that any raise would allow B to take back his chips and allow B to reconsider whether to call, re-raise or fold. However, if A were to call the full bet amount, B's chips would remain as a re-raise.
Also I would like a ruling on checking out of turn also.
Once A has indicated that they have been missed, it is at this point that all play should be stopped and taken back to the missed player. It should also be explained to the missed player (In this case A) before they are given their options that any bet would allow B to take back his chips and allow B to reconsider whether to call, re-raise or fold. However, if A were to check, B's chips would remain as a bet.
As the Tournament Director, I would issue a warning to B as a first offence or a penalty if it is a re-occuring offence. If this is in my Casino, I would also talk to the dealer (After their rounds) and make sure they are following table games procedures. But that's just me.