This indeed seems like a mileage broker, and in that sense, tickets purchased through them are most likely invalid whenever the airlines catches the trick which I would imagine happens often.

Having a valid confirmed reservation is a prerequisite to all regulatory protection so at this stage I would have thought the op’s position has to be evaluated via a vis the shady agent, not the airline and I’ve no idea what it entails except that if it were me, I’d likely try to cut the loss and run as far away from them as possible and ensure never to approach their dodgy website ever again.