I have had some 3/4" wenge plywood in the shop for a few months, laying flat with several other flat (and heavy) pieces on top and I'm beginning to see one of the sheets beginning to bend a bit at the corner. Although I haven't lifted all the plywood off the top of it to see how far the bend is into the sheet, I can see a substantial amount of lifting (~3/8") between it and the sheet below along one side.
I've paid close to $200 per sheet for this stuff and I'd hate to see it become useless.

So,
1. Is this common...should one expect this to happen with 3/4" plywood of this quality?
2. Can I "fix" it, or mitigate any further bending?
3. Justify returning it based on this bending alone?
4. Do anything in the future to prevent this.


Thanks.