I can only refer you to your own local department of education, to trace records so old or even find out if indeed this was a state certified institution. Most situations like yours usually result in recertification which requires retaking a GED test/course.
I guess we know why they went out of business, they didn't do their job properly. You are hardly alone as many are finding out now that many online colleges/HS's are bogus, not saying that's the case with your defunct company, but I can say with a lot of experience that its easier getting recertified with a GED so you can be employed than looking for 14 year old records.
If any one has those old record, or can point you in the right direction, it's the state/county government.
To add, seems you were not alone.
https://www.askmehelpdesk.com/home-s...rk-501884.html