If the case is filed in District Court, you will need to file a Motion to Vacate under Maryland Rule 3/535, within 30 days from the date the Affidavit Judgment was entered. You will need to demonstrate that you were not served or not served properly. You should go to the Court Clerk's office, and ask to see the file. In it, there should be some indication (usually on the outside of the file jacket) which indicates how service was effected. If no such evidence is in the file, your statement to that effect should be included in your motion. The Rules of Procedure can be tricky, so it may be worthwhile to consult a civil litigation attorney, who will be familiar with the process.
As counsel suggested, you can file a Motion to Vacate which, if you weren't properly served or notified of the suit, should be granted. This will essentially "re-set" the process; however, since you are aware of it, you will be able to participate in the legal process.
The information provided herein is general information only and not legal advice. The information provided herein does not create an attorney client relationship and is not a substitute for having a consultation with an attorney. It is important to have a consultation with an attorney as the information provided in this forum is limited and cannot possibly cover all potential issues in a given situation
You have 30 days to file a motion to vacate after judgment has been entered. After the 30 days you can still file but must be on limited ground such as non-service of the summons.
Here's an article that discusses the issues in greater detail. http://donnellylaw.wordpress.com/2014/02/19/in-brief-vacating-a-judgment-in-marylands-district-courts/
This is not legal advice nor does it create an attorney-client relationship. This is for education and informational purposes only. It is always recommended that you contact an attorney with any concerns as each individual case is unique.