A: This is an unfortunate situation, but these types of misunderstandings do happen. You may want to find out who the person at the register was when you were there. Once you know who it is, you can find out if they remember you going to the register that day. You can also potentially subpoena Wal Mart's sales records or video recordings. Also, if you paid with a credit card, you may be able to use your own banking records.
A: I am very sorry to hear what you went through. Technically you may still report this crime to the police/county DA, but I think the lapse of time makes proving your case problematic in a criminal context. Your best option is to seek a protective order as soon as possible. This can be done fairly easily, through the county DA's office or with a private attorney.