Bieng ****** at FNB (Request for CCTV)

I had bad experience at FNB standerton branch, I went there to withdraw money inside the bank around half pass 11 to 12 today, i withdrawn an amount of R98000.00 then i went back home and count the money was short with R20000. The distance to my home its about 5min drive, then I went back to the bank and tell them that an amount they gave me was short with R20000,00 and requested the camera footage , they refused to show me. They told me that i have to wait for an expect. I wont lie about money bieng , why today? I trusted FNB with all my heart and my husband has banked with them for the long time but losing R20000 just like that, its so unfair.