I'm so sorry, that must be so frustrating! I don't have a lot of add to what people have said, but maybe try a completely different method of basting. I like pin basting myself (use LOTS of pins, and if you're not using a walking foot, use even more), but there's hand basting and white glue, and possibly others I'm not thinking of. Instead of practicing on your quilt, try sandwiching two pieces of fabric and the batting and experiment with different ways of basting until you find one that works.
The other thing is if you can get someone experienced with making the quilt sandwich to work with you, the two of you might figure out where it's going wrong. Really, truly, good luck.