Return the chairs immediately and apologize to the store, while try to pursuade them not press any charges. Don't think they would not have a camera. Maybe they do.
It does not matter being caught or not. At the moment you took the chair, you committed larceny. Be a responsible person and be a better person. You did the crime, and you must take the consequences. If your children did the same thing, are you going to tell them "not to worry because there is no camera ?"
Returning the chair will be the only choice for you. Even if the store insists on pressing charge, you may still negotiate a deal with DA because $30 is not a grand crime.
For those of you suggesting not to return, you may be committing a crime of misprison as well.