How can I upload my credits for shows that are off-air, and have lapsed contact with the production companies.

I was free-lance for a number of years in Reality TV working in various positions, mostly casting producer and associate producer. The shows are not on air or streaming anywhere- they were mostly cable home design or reality. I have two IMDB pages with some super random credits - Brian Small (II) and Brian Small (V)- which I can't seem to merge. 

I have tried sending old call sheets with my name and credit, but that got rejected- the companies I worked for have either merged, or just haven't gotten back to me- what can I do? I've tried several times, but I can't seem to get my page merged or updated.

I don't know how to get a hold of the proof they require- if the shows were streaming, I could screenshot my credit. I definitely don't have 10+ year-old contracts- and most of them didn't list show titles (for whatever reason)- just production company names.  

I am trying to get back into the industry after a half decade absence, and if any potential employers look me up, this might look pretty bad... none of my 'good stuff' is listed.   :(