Don’t want to get anyone in Monzo into trouble for not following protocol but I had a similar transaction reversed no questions asked, no proof of decline presented.
Exact same thing happened to me ordering a Domino’s on my phone app. App froze just as the monzo notification came through. I had to go to local shop where they said there was no order placed for me. I ordered again there and paid again with Monzo. It appears that in both our cases the process failed/froze after authorisation but before actual completion of transaction.
I requested the reversal of transaction, not because 18.98 would break the bank but just so that I would know if and when I could complain to Domino’s when/if I received other notification later on presentment.
In cases like this it’s essential that we have the authority to reverse a transaction before presentment, monzo are not out of pocket for this period of time and it may make a massive difference to some if transaction is of a considerable amount. Once monzo get hit with presentment I understand money may need to be taken and this turns into a different processes of disputing the transaction.