Not happy with service and incorrect order

The worst experience ever, the staff not very friendly. They made a mistake on my order and then they told me without an apology that it was the till that made a mistake,was not what I ordered. I had to wait an extra 10min for my order after that and also they shifted the blame. When the one cashier saw my face and the barcode on the till slip she said woah man, it wasn't me. I then launched a complaint on their website as per the slip but I haven't heard anything back from anyone yet. Pathetic really!