If I were you, I would ask to see the paper you signed that allowed them to take the DNA swab.
I worked in child support/paternity for a state. I did hundreds of swabs. I was ok with it, tho, as the results only went to ONE department, forbidden by law to be shared, and destroyed after 3 years. AND I got notice of the destruction. So I was ok with that. Of course, it wasn’t my DNA being collected!
The swab is used to test for medical conditions and drug usage that would affect your premiums. I don’t know the details as this was many years ago. However, cheek swabs are what are used for DNA tests so that is why I said that someone already has my DNA.
Who knows, maybe it has been disposed of, but it could also be like Facebook where everything is kept and cataloged. I don’t know for sure.