If you rack up a debt it doesnt just disappear if you refuse to pay...... if the prices do come down from mass non payment protest (which it wont) then you will stay need to pay what you used
What I think will happen is there will be a fund setup to help those in energy debt, and the worst debts will get help, in effect we going to see something that rewards non payment, kind of like how discretionary house payments work where many councils have a condition you have to be in rent arrears to even ask for help.
If you got two people saying they struggling to pay, but one of them is actually managing to pay, whilst the second one isnt (even if its by choice), the second one will likely be seen as the one in higher priority of financial assistance with a debt write off.
My elder sister throughout her adult life never seems to respect the responsibility of paying bills, during covid she rang the council to inform them her council house rent will be late, they proceeded to give her help from a council covid support fund which they setup specifically just for council house tenants which paid off her outstanding water bill, outstanding electric bill, outstanding rent and 100s in food vouchers, she told me it was the best part of a grand. If she wasnt in debt on any of those she probably would have got nothing, maybe some food vouchers at the most. She also has told me of how she skips paying loans etc. It doesnt bother her at all.