Money transfer

Good day Hope this email finds you well.. I got ****med buy a person that sells some goods that I was interested in, he told me to deposit money (R1500) at pep store of witch I did in Vincent East London. I then created a pin that I kept as our agreement was for me to send the slip via WhatsApp his number is ‪***‬ and send the pin when I receive the package. This morning the person was not picking my calls I then decided to go to the store in East London CBD to withdraw the money, when I got the I had my ID and the slip so that I can withdraw my money, I was then told that "the funds have already been withdrawn" Hayibo njani I haven't shared the pin with anyone one, how is it possible. The store then gave me the number ‪***‬ to call. So tell me how is it possible for a person to withdraw the money without me sharing the pin, is the an option to change the pin at the Absa ATM if so how, please tell me coz I want my money back as you system is not secured.

Regards Masizakhe Tyeni ‪***‬