Very Bad Service

On 29 November 2017 I made a payment for two paperback books. The transaction went through three times. I have been contacting the seller which said they will send me the books and refund me for the 2 duplicate transactions. To date I have neither received my books nor have I been refunded for the duplicate transactions. I am very frustrated at the moment and does not get joy from the seller. I have logged calls with Payfast but they can't do the refund without the sellers authorization. I do not know which route to follow anymore.