Russia is not obliged to pay Ukrainian bills. They're unreliable partners (both for EU and Russia), they have a history of blackmailing EU with threats to stop

Russia is not obliged to pay Ukrainian bills. They're unreliable partners (both for EU and Russia), they have a history of blackmailing EU with threats to stop gas transit (Ukraine, not Russia threatened EU!), they're stealing transit gas all the time. Besides, they're used as an enemy, as cannon fodder against Russia. Why would Russia feed them using our natural resources? What's our obligation? It's not their gas, it's not their pipeline (it was built by "soviet occupants").