I wear Adidas exclusively and the only problem I ever had I just brought it back to the retailer I bought it from. Not sure how they'd handle something like that but I'd call up who you bought it from first, unless it was from shopadidas.com. Then I'd call their customer service line.
Yes, according to their web page there is a warranty on their clothing if it is a manufacturing error which seems to be the case here.
I emailed them and my message has been bouncing back and forth between adidas Canada, adidas/Callaham golf department and an auto response system. Didn't have time to call yet and don't want to deal with the store where I bought it because I'd spend more on gas + time getting there than the silly shirt is worth.
I always liked their stuff and I think it's decent quality overall. Customer service and web page design trails behind a little.
I have lots of adidas stuff, many pieces are several years old now and I have never had a major problem. I actually find their clothing to be well made and quite durable.
That being said, did the problem occur in the washer or dryer? I'm suspecting you put it in the dryer and the stripe melted a bit and stuck together. I always air dry my stuff, never put it in a dryer.