ATM (Shell Triton)

First and last time I'll use this dump.
Had a £20 fuel voucher to use in the Shell app and also a £1 voucher. I clicked to redeem them and the app allows you to redeem both.
The till operator scanned the code and only the £1 voucher went off. I told him that both should come off as I have redeemed both.
He refused to help me, not helped by the fact they wouldn't let you in the store and had to try and speak through glass outside.
He offered absolutely no help to me and then got shirty with me when someone else was waiting to get served because I had to call my niece to put money in the account to cover the full bill and he couldn't serve them without closing my transaction.