Sounds like one of two things.
1. Trying to straighten out the batting after washing the quilt.
2. The birthing process. Trying to pull the whole quilt through the little hole left after sewing the whole thing together. And trying to get the batting to lie flat after birthing so you can quilt it.
For #1, the only thing I can think of would be to use a fork that will go through the fabric so you can move the batting around.
For #2, leave a larger hole for birthing. You could use spray adhesive to hold the batting to the backing. Then it will be easier to straighten out the top. OR you could use spray adhesive the hold the whole sandwich together and then quilt it and then put binding on.
Sue