Transaction went through unable to take items

Hi I've paid at Keedo East gate mall with Pay just now. System took my money (1st amount) then the store couldn't scan the provided code. The store calls just pay now and they say it's a technical error I must go home and they'll refund within 7 workings days. Sorry? The consultant for just pay now Chirstopher Williams a client service champion mentioned that that's the process there's nothing he can do. I must just retry and they will debit the amount. The error comes from WIGoup their systems cant theres nothing they can do. I had to leave the store empty handed, and with R500 less.