im not sure what to suggest to ya mate, i break a lot of springs but then i do really stupid things on my stilts, i got to the point with work etc that £70 for a set of new springs became a consumable, things will break and all that.
The only way i can suggest for you to stop breaking them is to use lighter springs as they have more of a tendency to go soft, rather than just snapping.
I hit this wall a year or so into my bocking life, and at times i got really p**sed off with it.
Only other thing i could suggest is hold out for the new stilts to drop, im sure there will be breakages to them springs too, but at least if pro jump are selling them you know you'll get top notch customer service.