That's a PITA with Riedell boots, however you don't need to use every hole in the sole plates when mounting blades. In new boots, the heel plate should have two screws in the adjustment slots, plus one more (permanent) screw installed after the blade position is established with trial skating. Your photo shows one of the permanent screw holes obstructed by a nail, so that means the other hole can be used for the screw.
FWIW, I complained to Riedell via one of the members here about this issue. The response was essentially "tough luck".
I'm sure that your pro shop has seen this before.