That sounds like an unusual situation. Why would a company not allow that unless they are paying a huge hourly wage. Most do not encourage it, but don't block it either. You almost never tip anyone in a grocery store, but that is because you go into it, you push the cart around, you pick out your own items, you run it through check out, either self or cashier and you bring it out to your car and load it yourself. Why wouldn't you tip some poor stiff a couple of buck for all the work they saved you. I'm sure you didn't get a reduction in the cost of groceries. If I knew that they blocked it and I knew if they were not paying extra to the help for doing it, then I simply would do my shopping elsewhere.