Changing energy supplier when in debit 12 March 2019 at 11:10AM in LPG, heating oil, solid & other fuels

Bounty1

Yes be posted about my high energy bills before and haven’t ever got to the bottom of it but it has continued to go up, I’m now paying a monthly payment separately to pay off what I owe (not what I wanted but had no choice) my question is can I change my energy supplier when I still owe British Gas money.