Official BMW ****

I took my 2007 BMW 550i for a diagnosis, 2 days later they called me in, they gave me a bunch of documents of about 18 pages, plus the account to be paid that was 2000 plus because I had asked them to do a small job, when I wanted a copy of the diagnosis they told me it's company property and instead gave me a quotation, this was not I paid for, I specifically said I wanted a diagnosis not a quotation, I left the premises being threatened of police arresting me, 14 pages of my cars diagnosis that I paid for are still with them, what a legal ****