I am relatively new at the lightweight backpacking.
The two companies that I have bought UL equipment from is from Henry Shire- Contrail and Mountain Laurel Designs- Soul Side Zip Bivy & Rain Mitts by Ron Bell.
I have not noticed any sewing problems with my Contrail…I have a trip this weekend and will take a closer look at the stitching on it. But I can tell you have I have used it extensively over the past year without any problems with the tent.
I can defintely say that Ron's work is just top notch.
This weekend I spent 3 hours carefully seam sealing my Soul Side Zip Bivy with eVent top and I have looked over every inch of the sewing that was done.
This work is amazing…clean, straight and tight.
By it's nature, I think that UL equipment needs to be handled with a little care so that it will last. It is light weight, not bullet proof.
One thing that I might suggest for you is to contact the person/company that you bought your shelter from.
One thing that I really have enjoyed when doing business with Henry Shire and Ron Bell is that they are extremely responsive to their clients…they know that the UL community is relatively small vs. the big box retailers and they take a personal interest in what they do.
If you check the forums, it is not uncommon to see the owners of UL gear makers posting responses to questions or to even personally respond to emails that you send directly to them.
Hope that this helps you….highly suggest that you give the company that you bought your gear from a chance to make things right with you.