Kohler wide spread lavatory faucet, both the hot and cold are dripping and water leaks out of the cold handle when either hot or cold are on.

Kohler's lifetime guarantee: they'll send you another set of ceramic disk cartridges; you don't have to even prove you bought the faucet.

Only I can't get the old cartridges out of the valve bodies or barrels or whatever you call them. Tried WD-40. Using a crescent wrench to hold onto the old cartridge nut, a vise-grip on the base of the valve body. It won't budge. I can see from the threads on the new cartridge that it's standard, lefty-loosy.

I've already spent money on the vise-grip and the handle puller, and lots of time, vinegar and WD-40 just getting the handle off and the escutcheon loosened so I could get at the cartridge but I'm about ready to give up and buy a new faucet - preferably from a company where life-time guarantee means something more than ten years and free parts that do you no good at all.

Any suggestions? As far as either getting the cartridge out, or the company with enduring faucets?