I've had mine for about 4 months (with a short brake (my wrist
)) I use them between 2 and 5 hours a week (weekend only) they seemed to brake in after about 20 to 30 hrs
I'm 17 stone and I got the heaviest (meant to take up to 18/19 stone )so they took a while to soften
The good news is that they should last longer once they are broken in
I also found that hopping helped for both my ballance and the springs bent more
I could jump higher on one foot than two at one point
So keep bouncing they will get softer