Can I sue for misrepresentation of my lifetime warranty?

I purchased a ring back in 2012 at my local Jcp. I also purchased a lifetime warranty the same day. I recently went back to jcp to have my ring repaired. I was giving a repair slip and told I will receive a call once my ring was ready for pick up. I received a call on 4/4/14 at 10:32am. The sale's lady then explain to me that the repair company is refusing to repair my ring because the repairs cost more than the actual ring and they wanted to buy the ring back. I refuse to take the money for the cost of my ring and instead asked that if I could have the ring return to me or if they could do the repairs in the amount of the ring cost and I pay the difference. I was then told by the sales rep that they decline and stated my warranty is no longer good. What it's a lifetime warranty.