Playing with my life now - no brake fluid after 4 year service done

After all the hassles I have had with the service centre of Tygervalley Multifranchise, after my 4 year car service- I got my car back (after a 2 week wait) and now my brake system indicator light is flashing? The brake fluid level is low, yet it was indicated on the service invoice that it was topped up and checked and they charged Liquid Capital for this - yet it was not done? I went out with my nieces and husband yesterday and I was afraid for all of us, due to flashing indicator light - what would have happened if my brakes suddenly failed - even my life doesn't seem to mean much to these people - I seriously cannot believe the audacity. I sent an email to everyone, include management (Jonathan, Eugene, Heinrich and so many more) including photo's taken of the brake fluid level - and not one response !!!!!