They use a bleach/water mixture to sanitize the changing tables after they are use. I think it's state code for them to do that, and to actually use bleach.
Yes, the fact that it happened even once is very concerning. We were told the issue would be corrected, and then it happened again. To me, there's a difference between negligence and gross negligence. The 2nd incident was gross negligence.
The bar for day care must be very high. Except for when Katy is sleeping in her crib/bed, she is never out of the sight of at least one of us for a second. They (the day care) needs to have the same expectations for themselves, and it doesn't sound like it's happening.
I don't think Gwen and I would have pulled our child out after incident #1, but we would have after incident #2. Yes, your child may have some temporary adjustment issues, but that's nothing compared to the incident #3 that you obviously want to avoid. (And I also realize the other issue...having any level of confidence that a new place will be better than the current one).