Don't listen to cops about how you should handle your case. He wasn't necessarily wrong here, but it's not a good policy. Look at my link below on how you can deal with police whenever you're in a similar situation.
Regarding the criminal charges, you need to get a criminal defense attorney. A theft charge is very, very serious. It's a conviction that will follow you around for the rest of your life. That's not to say you would be convicted of a crime, but the stakes are too high for self-help. There are many experienced criminal defense attorneys here, and if you can't afford one, you're also permitted a public defender. Work with that attorney for your next steps. They may be able to get you a deferment or misdemeanor compromise, both of which would end the case in a dismissal.
Regarding the civil demand letter, it's a request outside of the criminal matter so one doesn't necessarily reflect the other. If you retain counsel, they would also be able to work with the civil aspect and likely be able to resolve everything. Good luck!
If and until you and I sign an Agreement for Legal Services, I am not your attorney. These answers are provided for informational and/or novelty purposes.
Criminal convictions have serious consequences. If you do not understand what is going on you need to have a lawyer, if you can't afford your own attorney ask the court to appoint one for you, and talk to the lawyer about how to handle the case.
This response does not create an attorney client relationship and is offered for informational purposes only. Only a lawyer fully versed on the facts and circumstances of your case can properly advise you on the case. I am licensed to practice in Minnesota, not every state. You should always consult with an attorney licensed in your area on how best to proceed.
You should speak to an attorney as soon as possible, or if you cannot afford one, ask for a public defender. If you are charged with thet and have no priors, there are many options to keep the charge off your record.
The civil demand is a completely separate matter from the criminal case. They are allowed to request additional fees. An attorney may be able to assist you in negotiating with them. In addition, an attorney can discuss with them the possibility of a compromise of misdemeanor where the charge can be dismissed if the victim is compensated and agrees not to pursue charges. It is not a good idea to attempt to speak with Whole Foods yourself; you should have an attorney do this.