Sinister Diesel MKM Customs Will not refund money on lifetime warrantied product California

I purchased the Sinister Diesel Y pipe for 6.0 powerstroke in October 2014. At the beginning of June 2015, I found the Y pipe's driver side double slip joint leaking, and affecting engine performance. 

For almost two weeks I was back and forth with Sinister Diesel (mostly me contacting them) before I finally got an answer on how to handle my problem.

the Sinister Diesel 6.0 Powerstroke Y pipe has a lifetime warranty. They will not refund my money. My only options are to remove the Y pipe, and return it to Sinister for evaluation. They will replace it, at their discretion. When I informed them, that  thst was not an option, I was given another option... Buy another Y pipe, install it, return the defective piece for evaluation and my money for the new Y pipe will be returned, if in fact the original piece is found to be defective.

My two options for them were either, send me a MBRP Y pipe or refund my money. They did not accept either of my options.

The Sinister Diesel Y pipe has a lifetime warranty and the "Double Slip joints" that they use in place of bellows, are "gauranteed not to leak"

The Diesel forums are riddled with leak and fitment issues. Do not buy this product. They have lost another customer.