Can my landlord get away with accepting (stealing) my rent money for March while knowing the bank is forclosing on the condo in the beginning of March

Lawyers tend to separate problems of proof ("no proof of paying him any money") from the actual facts. The facts appear to be that you are occupying someone else's property on the understanding that you will pay for the use and occupancy of that property. The possibility that the owner of the property may be in default on his mortgage does not excuse your payment of rent. If you pay the money for March and the bank forecloses (which they can't possibly do without great delay and cost), chances are that the bank will be delighted to have you as its tenant.