someone open the mayo before we brought it and now we have to take it back. it was at kroger.

Yup, sounds like a good idea to return it.

I've seen people opening jars and packages when I shop. They want to 'try' the product. Can't figure out why they think it's OK. Let the store know and maybe they will keep an eye on things. I always try to buy the products with an 'extra' seal around the lid or ones with boxes that are securely glued or have those tape seals.