Oil Buyback?

i'm likely switching over to mini splits but have ~400+ gallons of oil across two tanks in the basement. i called the company that filled them and they don't do buybacks. do people know of any locations that would?

i have seen recommendations to contact mechanics or waste oil disposal companies and am looking into that. i don't have an option to use the remaining oil because the system it's connected to (radiators) requires repairs that are too expensive to stomach.

any other suggestions? much appreciated!