Improper information resulting in loss of funds

I went to KFC on Saturday the 1st to make a purchase. My card was declined as their card machines were offline but I was still charged on my account. I phoned the Absa call centre the same day this happened and the agent advised me to send an email to *** giving specific information which I did on the same day. I only got a response on Tuesday afternoon stating I need a letterhead from KFC. I went to KFC and they won't give me this letterhead as it i well past the day it happened. I followed everything that was advised to me but because I was given improper information from the call centre, now Absa will not refund me. Sort this issue out.