Checkers sixty60 shocking app glitch - resulted in double order

Checkers sixty60 app glitch: I placed an order today using the checkers app, as soon as I confirmed my order, I realised I forgot an item. I immediately selected the "update order" option, add the item and resubmitted my order. Then, to my absolute shock, I received 2 deliveries of the same items, with the 1 added item in one of the deliveries. I immediately contacted their help line to report their mistake. Their response was that the system showed 2 orders and the consultant speculated that what must have happened was that the store already accepted and started processing my order whilst I was busy updating my order, thus the app created a new order altogether. I said that surely there has to be checks and balances in place so that something like this doesn't happen. Why does the app offer an "update order" option then? They said that they would report the glitch to their technical department and that I would have to take the second order back to the store if I want a refund. There is nothing else they can do. The whole point of using the app is so that the consumer does not need to go into the store. Thus my options were to either get in my car and drive to the store for a refund, or accept the double order. To top it all off, one of the 6-packs yoghurt that was delivered to had a Best Before date of 01/10/2022 - today is the 6th of October - I asked for a refund for this. This was such a frustrating experience - totally unacceptable. The consultant did express his apologies for the situation. I definitely won't be using the app or service again.