Redo the borders. It will save you a lot of aggravation and you will be happier with the final product.

I would redo. Or cut the boarder narrower so the waves wont be so high.
the waves it is usually caused by how you layed your fabric before you cut it. Sometimes it helps to tear the fabric that way you know you are getting a straight on grain.
good luck.

Double your batting and use a mid-loft poly for the layer directly underneath the top. This will absorb the fullness of the extra fabric, which is what causes the "wave". Plan a quilted pattern that has some flow to it (a meander, a curvy stem for feathering, etc.). The extra batting will give the quilt a visual punch with lots of texture. If you're dead-set on a flat batting, and you prefer to avoid sewing in tucks or pleats, then you really have no other option that ripping and resetting. Good luck!

Other than ripping and remeasuring, etc. there is another "redemption" option. Yesterday someone suggested watching a video by Sharon Schamber on "Shrinking a block." She uses starch. I was amazed at the results. I found it by googling. There are three tutorials on shrinking and stretching a block.

You will be much happier with it (even if it takes a lot of ripping, watch a good tv show while ripping) because measuring the sides of the quilt and THEN making the borders the correct size after ironing and starching will make your quilt more appealing to you.

Here's a link that might help. http://topanchorquilting.com/pages/taming-a-wavy-border

Before you remove the border, have you tried starching it and pinning it straight and square (blocking it)and allowing it to dry completely in its blocked position? I block my quilts and usually don't have any problem. Then quilt as desired.

I always make sure my binding is taut, and stretch a little while putting it on. A little too tight is better than too loose. Just place the binding onto the quilt where it belongs with needle down. Place binding in place with a little tug. Hold it down with your fingers while it goes under the needle. Sometimes I even hold it at the back and lead it in as the feed dogs pull it. No wavy bindings.

I've steamed my borders when I found them to be wavy even when its attached to the frame. Another quilter gave me this tip and it does work. I now measure from the center out and rarely have much waviness in my borders these days.

As someone else mentioned, if too much wave I recommend tearing it out and redoing it as you will not be happy otherwise.

I've tried the go-around method thinking I would save time. It never works out well :-( It's best to just go ahead and take it out and fix it. If you don't, it will be more work for something you will never be happy with! Sorry.