NOT A GOOD START

I recently joined Bulb and can’t say it has been a good experience.
First it seems they are incapable of answering an email, offering online chat but it never being available and “technical problems” when you call so you can’t speak to them.
My previous supplier have informed me they received one final meter reading but not the other (dual supply obviously) so are unable to provide a final bill and reimburse me over £100 that is owed to me.
Am wondering if anyone else has experienced something similar and what you actually did to resolve the problem.

Final readings have to be approved by a 3rd party and they are done separately, then they are passed on.