SF-50 for prior agencies I work

Seeking an SF-50 from my last employer due to a lateral transfer to another federal government job. I worked at the VA hospital and now I work at SSA. I have contacted numerous offices, and the last office gave me the National Archives number. My HR for SSA has requested an SF-50 with no prevail. We were also told by VA that when they send it out, they don't know who or when they sent out my records. I worked for VA from 08-2011 thru 08-2014. Can you please assist in getting the document so I can sent to my HR? This is for my leave to be updated and it will benefit me for when I retire.