About my bill

I have recently switched from shell energy to bulb energy and both suppliers have taken payments of me? What do I do

I have recently switched from shell energy to bulb energy and both suppliers have taken payments of me? What do I do

Possibly the first thing to do is to read this Bulb article: https://help.bulb.co.uk/hc/en-us/articles/360000313371-Why-is-my-old-supplier-still-charging-me-