Adding a voice actor to a program

I submitted the voice cast list to the obscure tv special Return To Mocha but they wouldn’t accept Frank Welker’s credit even after I provided evidence, even though the version uploaded on YouTube cuts off the credits, he is listed here in this video at the hour and forty four minute mark as part of the voice cast:https://m.youtube.com/watch?v=Av9v8ISDSI4 He voiced Augie, Oscar, and the I.N.N. Anchorman.