Hi Mike,

I've asked the customer service team to get in touch with you, alternatively please get in touch by emailing info@mybuilder.com. I hope you are able to rectify matters shortly. Kind regards,

Ben@ MyBuilder

I'd contact them though they aren't helpful in case.
If you know the comp name you could look up who they are registered with
I've had lots of problems with builders on here

I have had a serious problem with a builder on My Builder. I have communicated with them and they are not interested. I seriously question their vetting procedure. I will not use them again.
Personally stick to word of mouth and people you know who recommend someone.

I would send MyBuilder an email and outline the problem and ask if they would get in touch with the gas fitter as they must have his details on file.