Builders give themselves early Christmas present. **** me R4000

I purchased an item from builders 4 weeks ago. I did not receive the item, nor did I receive any communication about the order. I decided to cancel after 3 weeks of waiting. I called on Monday the 19th for a refund. Very bad service as I was made to wait and sent from pillar to post. I was told the money would be back in my account in 3 days time max. It's now 5 days later and I have still not received my money. Builders have a lazy approach to service, no regard for customers at all. I want my money back immediately and a formal written apology for this bad service.