My record indicated I was convicted for theft by check

The court record should show the outcome. I am in PA, but in most states a criminal history check will show arrests even if the case was dismissed. You, have to expunge the arrest records or they stay in the system. Talk to a local attorney.

If the court was a county or district court there should be a judgment that you can see at either the county clerks office or the district clerks office. It will reflect the type of disposition that was entered. If the disposition was deferred probation you may be able to get a non-disclosure order  or an expunction (if the offense was a Class C misdemeanor). In any case the record should be available for you to view and obtain a copy.  Based on the amount of fine ($2000) I would expect that this was a felony. If so, you may have been given a pre-trial diversion. If so, you may not been convicted. A non-disclosure order is also available for this type of disposition.