Im with you, hate paying for something that isn't up to scratch. (restaurant meals especially & if I don't get a good meal for the money, wont ever go back there) Its getting more common for businesses not to care if the customer is satisfied.

Whats with the seam/join near the bottom of the sides?

With a bit of luck the vinyl will tighten up a bit over time. You did well making the seats look as good as they do

cheers
Max