Officer, would you let me explain how my driver's license got suspended?

I moved to a new apartment and so my mailing address changed. I usually get a reminder through the mail to get my car tag renewed. I had my mail forwarded to my new address but for some reason I didn't get the reminder to renew my car tag. The post office probably thought it was spam or advertisement or something and didn't forward it to my new address. So my tag end up expiring. I got pulled over by a sheriff's deputy and got a ticket for an expired car tag. He told me that if I go and renew my tag and show him proof that it was renewed, he would take care of the ticket. So that's what I did. I went and renewed the tag and took the receipt down to the sheriff's office. The receptionist made a copy of it and told me that the deputy will take care of it. Now, three months later, I got a letter in the mail from the state's department of safety telling me that my license has been suspended because I didn't show up in court for the expired car tag. Well, I thought the ticket was cancelled, but apparently the deputy neglected to do that..