I realise that in the German language as well as in other European languages it is acceptable to refer to someone as “My dear…whatever”.
In Australia, however, this sounds patronising and sarcastic.
Our Australian culture is much more casual than the German one and even irreverent at times. We don’t bow and scrape and act obsequiously even when we are courteous. So being called “”Dear Customer” is strange to our ears, especially when the announcement is “Dear Customer we are closing Checkout 2. We are opening Checkout 3” and you feel like clicking your heels together and saluting “Jawohl”.
Dear Aldi, you can always simply announce that you are closing a checkout by saying “We are now closing Checkout 2 and opening Checkout 3. Thank you.”