I got some backing and I am in the process of pinning it on thanks Sharon..

I went and spoke to the lady at the shop a week or so ago. Our conversation was a challenge. She explained that she used the fabric over a year ago for a grandchild's quilt, from the same bolt and she was sure it was washed weekly and nothing has happened to it (though I doubt a DIL would say anything) she went to find a picture of it on her phone and never found it. She also said that the fabric was from a reputable Japanese com. and that she only uses a rotary to cut her fabric. When I showed her what happened to the thread she said it wouldn't bother her, but that she would take it back. She also explained that she had quilts in the shop over 100 years old… but what was the quality of the fabric they used to start with? The old ones that didn’t last could have been made with lesser quality.

I told her I was still trying to decide. Anyway, I have decided to take it back. Too much work has gone into my blocks to guess now. I showed her the fabric I had gotten for the back and she said it too was a good manufacturer (I bought it at Hobby, I didn’t share that with her). I did the same thread pull with this fabric (also 100% cotton) and it did not come apart like cotton candy. Her only comment to this was that she never heard of pulling threads to make a straight raw edge.
We never saw eye to eye, I felt uncomfortable. So, I will return it and go looking for a replacement.