Bad service

My husband bought the wrongs size diapers. I went back the very next day to ask if I can change it for a bigger size. The lady said no they don't exchange baby stuff. I said I understand that but the package was still closed and untapped with. They just said no. I phone the manger who told me a story about people changing the diapers for **** ones. I told him they can Inspect it and see if I tempered with it. But they were unhelpful and just because they had scaly customers before all the other customers now have to be met with. I feel that it is so unfair of them to do this as all customer are not ****** but some of us do make mistakes and for them to be so unicomodating is really not fair and also not customer friendly.