iphone4 home button super sensitive

hi

my iphone 4 home button is super sensitive -- a gentle touch acts as a single click, a single click a double, which means a normal click won't close applications etc.

i've taken it a shop that replaced the home button last year, this time they replaced the ribbon free of charge but still no difference

ive tried most solutions to recalibrate etc .. any advice?

the shop says they also tried a new home button but still no use?

thank you