Unknown charge

Hi all! I moved into a new place on the 23rd last month and chose bulb as supplier. Turns out the previous tenant was also using bulb. I put in my new address one day before moving in and set the direct debit for the 27th of this month. Haven’t been charged so far, but I just got a bill in the mail asking me to pay a huge amount for the 7th to the 22nd of August, when I wasn’t living here. My guess is that it was meant for the previous tenant and they just didn’t change their address on the website, but since there’s no name on the bill how can I know that I won’t be charged? The bill is nearly £400, which no matter how the previous tenants lived can’t be right for just a couple weeks. Any help would be much appreciated!

Contact Bulb direct and discuss. Utility companies supply buildings not people so the bill is charged against the property.