FNB gives **** money from ATM

Hi, I went to draw money at the ATM in Shallcross ,Durban . Today .It was R700. I took the money and left for home . When I got home I saw R600 plus a FNB ticket . Which says re usable with a bank stamp on it . What BS is this . I contact FNB through the secure chat and was told to logg it on the dispute form . All this beacuse FNB does Strange things .pls sort out . I have the ticket or a pic if needed .