WTF to the manager at Walmart

So back story but my daughter left her weighted blanket in the car of her grandma and we had to go shopping and also get her things out of her car. So I packed it in her bag and went in to go shop. Well I had to open my bag to get my card and the manager seen me pull the blanket out a little to get to my wallet. I checked out but before then this guy was following me and my daughter all the way to the door to leave. Well he stopped us thinking we stole it. I called her grandma and she even explained that my daughter has anxiety and sleeps with the weighted blanket. The store purposely set the alarm off and stopped us. Asked and looked in my bag while I explained that my daughter has a broken femur and has anxiety so it helps her out. When he proceeded to say we stole it I called my mom and had her talk to him. I honestly feel like I was harassed in a way. U can clearly see she has anxiety and she started to get worried till I picked her up. Well my local Walmart lost a customer in which ik they don't care but man wtf. What would u ladies do if that happened? Ik they was only trying to do their job but when they continued to ask and ask to the point of me calling my mom and I felt this way. Even my husband is upset. Like idk what to think. And my daughter is a mess right now.