http://www.wattscanada.com/faq/regulators/main.html
Check your water pressure, and install a new fluidmaster 400A.
If the pressure is over 60, then that is probably the primary reason for the issue of breakage.
If those disks or blue toilet cleaners were used in the tank, that also contributes to the failure.
“Your best interest is secured by making the right decisions the first time.”