Smart meter installation

We had an engineer attend and he fitted the electric smart meter but said that we should rebook to get the gas meter done as he was unable to complete it on the day. I am trying to book it but cannot find a way to do so online and am unable to find a contact number. Can you help please?

Contact details are at the foot of the Help page:

https://help.bulb.co.uk/hc/en-us