Sixty60 checkers *****s from their customers!

I ordered groceries on the app. My funds were transferred to Checkers. I then received a notification that payment had failed, but the funds had left my account. Call centre agents (3 of them) said it was a "glitch" and my delivery would be fulfilled. I am still waiting. I have asked for a refund and they promised to call back but so far no response. Checkers is a big corporation but does not seem to have the capacity to sort out my little order. Please refund me immediately.