are these on a set of hayes 9 or hfx mag brakes? If so, it happens to alot of them. I ran a set with a zip tie around it to keep the lever from popping out for over a year without any problems.
Most of the hayes levers and pistons are cross-compatible....so if you found a trashed stroker, you could put the lever on your caliper. but this is all alot of work for old brakes