Ask HN: Any way to recover deleted surveillance video from DVR

Thought I might ask HN...in short some serious crimes happened to me at a gas station (abduction/kidnapping), I did everything I could to preserve the video, but as you might expect the gas station did not preserve the video and allege it was over written within 7 days.

I went in person to request the video 2 days after the crimes against me (and to file an incident report and request the name of the insurer), the employee said she would call the owner/manager to help me but actually called 911 and had me removed from the premises.

Then I reached out to the corporate franchiser (Sunoco) to request the name of the franchisee to serve a notice of preservation (required under state law), of course they dragged their feet just long enough to delay service of my notice.

Now the insurers (Berkshire Hathaway - Berkshire Hathaway guard) and their scumbag attorneys are alleging the crimes didn’t happen to me and if they did they didn’t happen on the property but across the street (they even published a written statement online to this effect, which the judge said isn’t defamation and that I am just taking this to personal), notwithstanding the fact the guy was caught and sentenced to a total of 80 years in prison.

I’m sure I would need the make/model of the surveillance system DVR for a solid answer, but in the meantime, I thought HN would be a great place to ask if there is any hacks or hope of recovering overwritten video from these types of systems?