I had trouble with transferring labels to fabric sheets I purchased too. Had to go buy a different kind. I have moved since and the "good" kind is packed somewhere! or I would tell you what worked for me. With the second fabric I washed the printed sheet before I added it to the quilt. When it didn't not run, etc. I figured it would be ok. I know some people send their photos out to have someone else do a phototransfer. That seems to work quite well too. One lady I met uses an Epson printer for photo transfer.
Otherwise! --- how about just putting in another block as suggested above? I have replaced blocks even in the middle of a quilt when I was not satisfied with what was already there or when I discovered two pieces of white on white sashing was wrong side out! Then if you have succeeded with the printed info on fabric later you could always handstitch it to the back of the quilt as a label.
I am sure you will figure something out and end up happy with the outcome.
Happy Quilting!