No refund for double payment to supplier

On the 30th of November 2015 I did online shopping at Dischem, and mistakenly paid them twice using FNB online banking. I immediately informed FNB (01/12/2015) and after confirming this double payment, they told me that it is reversible. <br> <br> I got a form to fill out and send back. I then got a response email stating that the request will be processed withing 5 working days from the date of response. Days and weeks have elapsed without the resolution to this matter. This is after I continuously contacted FNB, and being promised a call back. At 1 stage (after weeks of delay) I was informed that the matter needs to be escalated. I had to call them back to get the feedback, only to be called back by an *********** employee who couldn't resolve the matter. To my disbelief, he informed me of the 30 day period for such requests, And that I should contact the supplier myself! LIKE, REALLY???!!! <br> <br> I find this disgusting and irritating. I expected a better service from a big organization like this. This is the last resort, after the last call I got last Friday, hoping to get a satisfactory response from a competent employee.