Send in a paper return. If you file your own return, this will supercede anybody that claims you as a dependent. They will take it away from the person that claimed you.
Send in you own return. Since someone already claimed you, you will not be able to efile and will need to file a paper return. The IRS will take care of the rest.
Any individual seeking legal advice for their own situation should retain their own legal counsel as this response provides information that is general in nature and not specific to any person's unique situation. Circular 230 Disclaimer - Advice given in this response cannot be used to eliminate penalties with the IRS or any other governmental agency.