What's the warranty on Manhattan Portage bags?

I bought a manhattan portage bag a few years ago. Unfortunately, the lining in the back pocket has separated from the rest of the bag and I'm worried about the problem getting worse.
1) Can I get this fixed under warranty?
2) I can't find the receipt. Will this be a problem?
3) I'm in Canada. Can I mail the bag to you? Alternatively, can I get it fixed the next time I'm in New York? How long would it take?

Apart from this problem, it's a great bag. I'd hate to have to replace it. I don't know what kind of bag it is, It's like a west side bag but with fewer pockets. I bought it in the brick and mortar store.