I was picked up in Walmart for shoplifting and received a summons and court date for unlawful concealment. Hired a lawyer and when we showed up to court, they couldn't find my name, the case number, or officer's info anywhere in the system. They signed off on the summons as dismissed. That was three months ago and last week I got a letter in the mail from the court with a new court date. Since then, I've gotten a job, Im in school full time and really thought this was behind me. Now what do I do? Was my case dismissed?

It depends on how it was dismissed, with or without prejudice. It could have been dismissed so that it could be reinstated once they found the paperwork.