Me too frozen handle -very frustrating. Though Pfister support and warranty is exceptional, its not the first time I have to call to have a part replace other than a cartridge. This faucet is less than 5 years old! Here is my advise, charge whatever it takes and make them to last, and for goodness sake, place your logo or brand name somewhere visible and a Product QR code tag to fittings underneath counter and a removable spare label people can affix to the inside of their cabinet!

Furthermore, emboss, print or whatever part number all parts!!!

Is this too mush to ask?