No service

I transferred money from my Canadian bank account back at the end of June into my FNB. However, it was meant for my sister and I rejected the forex transaction on FNB online. I have struggled since then to get an answer from 2 different bankers on where this money is that was supposedly returned to my Canadian bank. My Canadian bank also say they have not received anything, the only proof FNB could show me was a screenshot of a transaction with no Swift confirmation and my incorrect address on the “transfer”. Can someone please assist me in getting my money back as it is almost R40K and it’s been almost 3 months with no help from FNB.