Nautica T-Shirts Underarm Deformation Despite Careful Washing – Not User Error

I purchased several t-shirts from Nautica, and the underarm areas on all of them have started to deform, as shown in the photos. I recently sent one of the white shirts for inspection, but Nautica claimed it was due to "user error." However, I’ve experienced the same issue with most of the t-shirts I bought from this model. Is it really possible for this many shirts to have the same user error? I always wash these shirts separately at 30°C because I love them and want to prevent any damage. This kind of quality issue is not what I expect from Nautica. I request a proper resolution for these defects, as they do not reflect the brand's standard.