You are not overreacting to this, it's your daughter and who else is going to look after her like you? Ask your daughter as much as you can about her day. I've had my two boys in two different daycares since they were 1. It was hard because they weren't able to talk to me about their day, so all I knew was what the teachers would tell me. Since your daughter is almost 4, is she able to tell you how the teachers treat her (aside from the obvious wiping issue)?
There are teachers that teach and do their job and there are others that also get to LOVE your child, and that's a blessing. One of the daycares my boys were in was also the best in the area, yet there were a lot of little incidents and it was apparent that the owners were just in it for the business and not the children. They ran things smoothly, followed procedure, but there was not a lot of connection with the kids. The one they are in right now (my 3 yr old) has an awesome staff, beginning with the owner. They do the same as the other daycare, but offer people that really care about kids, which honestly, with the guilt of leaving my son in daycare all day, I really want him to receive that love. They are able tell me DETAILS about my son when I pick him up. He even tells me he loves to go to daycare.
Sometimes the best daycare is the one with the better staff (with curriculum of course).
Also, if they are not allowed to wipe your daughter, did they let you know about this policy?
Hope this is resolved. I know it can be PAINFUL as a mother to leave your child in someone else's hands and you know she may not be taken care of.