Bill from before I moved in + Account closing

I’ve been having an issue for a while now which is that after a few days from moving into my new house (18th July) I received a bill dates from the 17th of June , one month before actually moving in. That bill was added to my bulb account and I then called costumer services to try and sort it out. They told me they would correct the move in date and would contact the landlord/letting agency to redirect the bill to them. Nothing changed.
After one week I called costumer services again because not only did I still had that bill, but also the value bulb claimed I had to pay had gone up. Again same reply from bulb but nothing really changed.
Last week I received a statement threatening that if I didnt pay the said bill they would install a pre payment meter in my house. I called bulb again, for the third time.
This time, bulb actually asked me for my landlord’s details, and said they would correct the bill and I would get a confirmation email within the day.
After one week, still not having received the e-mail, I log into my bulb account which now says my account is in the process of being closed.

Does anybody know what I’m supposed to do?

Thank you kindly, Nuno

The only thing you can do is talk to Bulb again. In these cases try to deal with one person at Bulb and keep contact with that same person until it is resolved.