Credit gets accepted then removed after a few weeks

As the title states, my credit keeps getting removed after being initially accepted after a few weeks, or months. This has been ongoing for a year now. The film did not include me in the official credits (even though they promised I would be), but it was a very big film and a few people were missed, etc it happens. I am fine with accepting an uncredited credit which I am still being denied. I have submitted so much proof, pay stubs, crew list, callsheets, etc. 

can someone please help me