Payment date

Please can I change the starting date because my current provider still charging me till the end of this month and I’ve even got a bill from you although I’m not fully transferred over.
Please help because my account is -£98.74

Bulb charge in advance for fuel with the direct debit on the date you sign over, it should balance out as any credit from your old supplier will be credited to you when the switch over is complete.
If you still have concerns phone or use live chat to discuss with Bulb.

my current provider still charging me till the end of this month
They will only be charging you until your switch date. If they've sent you a bill for until the end of this month, the extra days will get credited back to you from your old supplier a few weeks after the switch date.