Help grohe rough in valve won't turn off

Hello, I replaced the lever adaptor in a grohe shower the valve is #35251
everything was great. 2 hours later the shower starts running. I keep resetting the adaptor but it seems the stem in the valve (brass). is busted. the ater continues to run no matter which way I turn it. Any suggestions out there?
Thanks
JamesV

I have had customers who had problems with this type of rough-in and the handle slipping.
There is a way to fix it but you need some o-rings 2 of a #01 224 000.
Grohe should be able to send you no charge if you explain the situation.

I have the instructions on how to fix but it won't upload here.
You can e-mail me you address and i can e-mail it to you.
peter@kleininternational.ca