Family Dollar complaint: Harassment by security guard

Hi my daughter in law is disabled. She’s been a family dollar customer for years. A couple of months ago her son which Is 4 years old grabbed a candy but her daughter took it from him to put it back. The security guard accused her daughter for stealing and said if she came back at another time with her daughter she wouldn’t be let in the store my daughter in law asked to see the video and he refused to show it. She left but at another time she went back she was going to buy me some underwears which she did. Next time she went into the store the security guard stopped her and did she had opened a pack of underwears which is not true. She again asked to see the video and he didn’t let her see it. Now this is coming to be a harassment. Like I said my daughter in law is disabled if this continues to happen we will seek advise of an attorney.