I don’t suppose this will do any harm but it is a gross exaggeration, in fact a delusion, to claim that “our collective power will force an end to this crisis.” How? The idea seems to be put pressure on the government to do something. But not even the government, with much more “force” at its disposal, can “end this crisis”, even if it wanted to. They can mitigate it to some extent by tax changes and hand-outs till the price of oil and gas comes back down to what it was but that won’t be before the war in Ukraine ends.
In any event, cancelling direct debits can’t bring down the price of gas.
Personally I don’t pay my energy bills by direct debit anyway. Hope that doesn’t mean I will miss out on the £400 hand-out that’s supposed to be on its way soon