I don’t live in the states but there’s similar systems in some department stores here in Australia and I suspect, but don’t know, that applicable law in these cases is broadly similar. The store and their employees aren’t law enforcement and can’t arrest you or have any legal recourse for you ignoring their demands to stop and allow your receipt to be checked. They likely also have the right to refuse service to you and deny you entry to their premises and so long as this isn’t being done for a small number of specifically forbidden reasons (such as on the basis of race for example) they don’t need a legal justification to do so. This would mean that refusing to comply with their receipt checking policy might be enough if they see fit, to decide to deny you entry to their stores going forward. Many large department stores are incorporating facial recognition and don’t it seems feel the need for proper informed consent beyond some printed signage saying that but entering you’re consenting, so the practicality of them doing this is at least a little bit higher these days but I guess there’s no way to assess how likely this really is.