The present reading is correct. A wrong digit was submitted previously. This reading has been checked and is correct. Please amend.
If you drop Bulb an email at firstname.lastname@example.org with details, they should be able to help. It may be helpful to include a photo of the meter just for clarification (as Bulb has to send meters readings off to the ‘industry reading validation process’ who may then say 'this reading is lower than previous/not within the boundaries we are expecting: therefore Bulb should reject it) - if Bulb has a photo of the meter upfront, it’ll save time.
If it’s only a small error (<10 units), I probably wouldn’t worry about it as it’ll sort itself out by the next reading.
@Gardening1968 If a reading had been given incorrectly last time then this new read will be shown on the new bill and will correct any inaccuracies in the previous bill. You will probably see that it is a credit.