I've recently been looking at cell prices as well; found a lot of online sites selling for around 450. My local pool store sells them for 600.

Doesn't seem legal for them to not warranty based on your purchase receipt. I would try and find a way to push the issue. Maybe a complaint to the FTC or BBB if goldline is a member. I am terrible at "negotiating" that stuff but it definitely sounds from what you've written like they should be required to honor their documented warranty policy (unless you don't have the receipt).

Just out of curiosity did you try the acid wash thing on your cell (instructions were given to me in the "T-Cell 15 bad?" thread).