Replying to Weird binding problem

I used to ride on Full tilt classics with Marker Squire bindings, until I realized that the toes of my boots were shifting up and down in the binding. This problem were more appear ant on the left boot (on both skis), which was also the boot with more wear on the soles. Because of the fact that the classics don't have interchangeable soles I decided to purchase some Descendants. However after purchasing them I noticed the problem was still there, except it was just as bad in both boots on both skis. The two pairs of boots are the same size. Unfortunately, since I bought a boot that's bigger than the recommended measurement for my feet (to allow room for growth) the store said they wouldn't be able to be returned. Any possible solutions in mind?
Thanks, Conrad.

**This thread was edited on Jan 28th 2018 at 6:30:49pm