First contact the customer and let her know the issue. If you are using a poly bat--don't! too slick! I had this issue one I made that had lots of those big plastic logos--the stablizer is harder to get to stick and require you use a pressing cloth and I worked from back when making it--but still doesn't "stick" as well. Also, if the t-shirts have polyester in them instead of 100% cotton, they need a lower temp on the iron, and if some of them then were 100% the iron would have had to be turned hotter--easy to forget when stablizing them. I would not recommend using a panto on these plastic like logos--I round that sewing thru them created lots of drag and they tend to "stick" to the needle and pull. But definitely contact the customer and have her take a look and see what's happening. Good luck!