Refusing to refund and not responding to messages

Ordered a meal at Mugg n Bean Carlswald Midrand on the 30 November'24 and it got cancelled. I have been waiting for my refund since the 30th November'24 and it's now 10 Jan'25. Have contacted them several times with absolutely no solution other than that they insist they have refunded me and I should check the refund invoice on the app. I've indicated that although that is what the app says, I didn't receive the refund and can provide my bank statement if they provide me with an email address in order for them to peruse and see that NO funds were received. I've been sending several messages from December too date and they've now resorted to not even respond to my messages. Pathetic service and I am appalled. I'd like to report this on a higher level before social media but not sure to whom as this is pure theft as what happens to their miscellaneous amounts when doing monthly recons, surely they should pick up that funds haven't gone through.