Kohler Shower Units Advice For A Shower Drip - Can Anyone Help?

Advice for a shower drip - can anyone help? - kohler shower units

I have attached a Kohler shower control and the delta of a shower head with hose. In the "off" position, the dripping of water from the shower head from time to time. Kohler said that selling the issue of effective control, and wanted an alternative $ 90. There are about 8 or rubber rings on the disk, the O-rings of the problem and can not control?