Please include all credits spending types on 'Credit Usage' screen.
Currently only credits spent on scenarios running is shown, but incomplete executions does not.
If you use 'Break' error handler without turning retries off, this can become very expensive (credits and operations wise) when setting up a system.
If there are other credits spending processes, please include them too.
'Credit Usage' screen should give the user the real picture and not a partial one.
Another option (I like it less, but it's easier to implement) will be to include an explanation in the 'Credit Usage' screen, to explain what processes can spend the credits in addition to what's reflected in that screen and some advice, on how to reduce it.
In my case the advice could have been: remove incomplete executions and turn off the endless retries on each 'Break' error handler on my flows.