Double payment taken off my account

Hi On the 3rd May I had purchased of R259.97 at Jet Store which was deducted from my account moving my account from R976 to R716. And put to the reserves for later processing, my available balance was reduced. So today again the same purchase has been deducted. You deducted the same amount twice. I had a balance of R3 and R1277 was deposited and my balance should have been R1280 but FNB deducted the R259.97 again