I'm well aware of the technicality behind pending and non-pending (processed) transactions. If you go back and read my post... "They (ING) promised (even in their T&Cs) that payments would be debited at the end of the day. Yet payments still remain unsettled on the account for up to a week and aren't reflected in the total balance."
Even the more "traditional" DKB or Sparkasse does this for their credit card. Yet ING seem to be fairly incompetent with regards to changing from the way card transactions used to be processed to what their terms and conditions state... so no: They're not doing accounting right! Transactions should be debited at the end of the day (as with any decent debit card) as in their T&Cs or shown as pending and deducted from the overall balance - which they do online, but their app seems to be unable to subtract. Either they improve on the current situation or just leave it completely. But as with many things ING has just done half a job - and not especially a good one. The best implementation is by Revolut: You get your available balance shown immediately and pending transactions have a little clock icon next to them. This is how it should be with all banks, giving a full overview of what is going on. The worst is with Deutsche Bank. I pay and the balance doesn't show up (nor the pending transaction) until it has gone through. Not nice, but still better that way and the correct way of dealing with the balance.
After the debacle last year with ING calling Apple Pay a "hype", mucking up the transition to the new banking app and destroying their own workforce, I feel like going back to the partly more traditional banks (may I name Sparkasse or DKB?) and some more progressive ones is the best decision. ING seems to be caught up inbetween, throwing in some "agility" and making large numbers of long-time employees leave. Not good, not good at all...