Rock, I don't think they have to have your passport in order for the RP to have been issued. The MOI would have issued it and it's in their computer. Stamping it in your passport is just a formality so you have a copy to show. If your RP hasn't yet been processed, your company would have to stop it in order for it not to be valid. You certainly can still quit under the probationary terms bu the NOC is still the problem.
Mandi