Duplicate Payment

On the 16th of December a ducplicate payment through payfast went off on my account. I immediatly contacted the vendor and he said when it reaches his side he will process a refund through payfast. A week later he said he did not recieve the funds on his side and he contacted payfast and they told him that I need to contact them directly. Immediatly I sent a query to payfast Re:[## *** ##] Duplicate Payment Only to be told the vendor needs to contact payfast. I explained to her that I did that and now I am getting the run around. I provided all the information in my initial request and the same information was requested even though it was provided initially. I sent them an email as such and no response as yet. What do I have to do to get my money back?????