Had a new smart meter installed in Aug19 and meter readings have been submitted to Bulb for electric and gas on the 1st of each month thereafter. My account is now in substantial credit, however Bulb have not taken the money off for my usage.
Call them, that’s the best way. This has happened to me twice in the last 8 months. I called at 12.30pm during the week and got through in about 3 mins. Don’t email them, it takes forever.