Taking payment but I'm not a customer!

I left Bulb’s dire service mid June, and yet for some reason my direct debit was taken out at the start of July. I’m pretty sure payments are made in advance e.g. pay 1st June, for usage for the whole of June. They’ve taken £60 from my account, and customer service seems non-existent - no replies to tweets, emails etc. Why on earth has this happened? It’s put me into my overdraft.

Mid-june was only 2 weeks ago. Your account with Bulb almost certainly hasn’t been fully closed yet following your switch away. The circumstances are similar to what’s described in this article,

only in this instance Bulb are the old supplier that are still charging you.

This is fully expected and documented during a switch of energy supplier, and needs to be budgeted for when switching. You’ll never pay for the same energy twice, but it might take a month or two before it all settles down and any cashflow issues are resolved.