In defence of the long arm quilter:
if you insist on not correcting the wavy borders please do not blame the long arm quilter if you have tucks and still wavy borders when it is returned to you.
There is an old saying - an ounce of protection is worth a pound of cure. Measure thru the middle of the quilt either vertical or horizontal. cut that border fabric to that length X 2. Now divide your quilt into 4th's and the cut borders into 4th's; pin together at the pin sites. When those borders on sewn then do the same measurement to the remaining border. There should be no waves. I hope you try it - it works.