Money withdrawn without my knowledge

On the 1st of October 2015 there was money withdrawn from my account. About R18000 was withdrawn at around 15:52.03 from cheque account. Other amounts of R5 000 at 14:27:24 and another R5 000 at 14:28:13 withdrawn from Savings account. Further more an amount of R1730.83 was used at SPar-Tops, R91.80 at chicken licken and R140.80 at N4 Rosehaven South. All of these transactions happened in Middleburg (Mpumalanga) while I was in Bloemfontein. My cards where with me together with my ID. I contacted standard bank and opened a ***** case. They said they will open separated cases because R18 000 was withdrawn inside the bank and R10 000 at an ATM. On Monday the 12th I called them trying to find out what was going on. I was told that the investigating person said there was nothing found to be wrong about the withdrawal at the ATM. They are saying my card was compromised and it does not show any ***** committed because the original card was used. My question to them was how can the original card be used while it was with me and I was in Bloemfontein by that time. All I want is my money to be returned because I gave no one Authorisation to withdraw money.