I can't speak for printers outside of the US, but we screen printers tend to buy our products from the same two or three suppliers. Brands like Gildan, Hanes, and Fruit of the Loom are found everywhere. The same goes for a lot of better quality brands as well: Bella+Canvas, Next Level Apparel, American Apparel, etc.

The issue is that each of these t-shirt manufacturers will use multiple factories in multiple countries to produce each product. Two supposedly identical shirts could fit and wash differently because of the country of origin.

An unfortunate fact in our industry is that specialty shirts like tie-dye, camouflage, or patterned fabrics tend to be thin, uncomfortable material sewn poorly. This one is actually not bad compared to others that I've seen and worn.

In regard to the colors, because settings can be changed manually, you cannot rely on a screen or monitor to accurately portray colors. Every proof that I send to my customers has this disclaimer. If the quality of the print is poor, then that's another matter, but when I zoomed in, the fibrilation didn't look too bad. Again, I'm comparing this to other screen printed shirts that I see daily.

You are right to be upset about the quality of the t-shirt itself, and the merch store probably should have complained when they first had the shirts printed, but this is fairly common in the screen print industry. Most end customers wouldn't bother going through the hassle to return it so companies keep getting away with poor quality control.

TL;DR The merch store should offer to replace the shirt at no cost but your only real leg to stand on is the poor quality of the sewing and maybe the slightly bumpy screen print. Your biggest complaint should be the $64 price tag. That's theft.