2 purchases made for MiniMiner @ 745

My son just made two purchases at 745 points for MiniMe Miner ores.  The first one didn't seem to work.  So he did it again and that didn't give work either.  He's made 2 purchased for ores and either worked. HOWEVER, BOTH ATTEMPTS TOOK  HIS POINTS.  

He's very upset because now he only has 50 points left and that's not enough to get anything.

We are new to this so please help me figure this out.  My son worked hard on chores to acquire the funds to purchase MiniMe Miner mine points and he's eager to keep moving forward.