Poor Service from FNB consultants

I made an online purchase on the 20/11/ 24. The purchase was credited on the same day. I was informed that the money would reflect back in my account with in 5 - 10 business days. It has been almost a month and still nothing. According to the company I made the purchase from they have sent the bank and authorization number for the credit. I have received an email from the bank showing the money was deducted from account. Yet now when I check my transactions for November this transaction has disappeared. When contacting the bank no one can give me answers as to what happen or when I can expect the refund.