Money gone missing

In June 2018 I invested an amount of R780,000 in a money market account at the Cape Town CBD branch. I was assisted by a financial advisor named Mr Khan who was stationed in a cubicle inside the branch. He advised me to invest in a money market account and also advised me to do a money gram where I would receive my capital plus interest in dollars. I agreed and signed and he handed me proof of my transaction. After two weeks I went to the branch because I started noticing withdrawals from my account. The staff at the branch advised me that there was no Mr Khan and that they didn't know anyone like that, I don't understand seeing he had a name badge. I was so frustrated and shocked I didn't know what to do and did not think of pursuing it any further. However I do have my proof to support what I have stated. All I want is for the bank to refund all my money. I can be contacted on the numbers provided