I did File and Suspend before Apr 2016 (turned 66 in Sep 2015). My plan was to not take SS until I turned 70 (I have a military pension). Unfortunately for me, I now have cancer with a very low 10 year survival rate. I called our local SS office and asked how much my lump sum payment would be and was told that this payment option stopped. I thought that when I signed up for F & S before Apr 16 that this would still be there.
I'm sorry to hear about your prognosis.
If you voluntarily suspended your benefits prior to the April 30 2016 deadline, then you can request reinstatement of your benefits retroactively and claim a lump sum payment of the accumulated back pay. If necessary, you should be able to prove this to the representatives at your Social Security office by directing them to section B. of the following reference from their operations manual: https://secure.ssa.gov/apps10/poms.nsf/lnx/0202409130.