England head coach Eddie Jones was unhappy with Italy's tactics, including their refusal to form rucks.
Despite Dan Cole's early try, Eddie Jones' men trailed 10-5 at the interval before second-half scores from Danny Care, Elliot Daly, Jack Nowell (two) and Ben Te'o secured a 36-15 victory and a bonus point at Twickenham.
The win moved England back to the top of the championship table and kept alive their hopes of a second successive Grand Slam.
But Jones said the game against Italy wasn't rugby today and complained about their tactics in a post-match interview.
Jones said that paying spectators should ask for their money back, and that he should refund his day's wages to the Rugby Football Union.
"That wasn't rugby"February 26, 2017
The Australian threatened to retire if the tactics - which saw Italian defenders stand in England's back line as no offside line had been formed - prevailed in future.
Jones said: "In football they say park the bus. I don't know what they had, but it was bigger than a bus.
"Remember Trevor Chappell? Bowled under arm along the ground. Couldn't hit the ball for six. We saw a Trevor Chappell game of rugby today.
"We still haven't played a game. We haven't played rugby yet.
"Congratulations to Italy. I thought they were brilliant in the execution, but if that's rugby, I'm going to retire. That's not rugby.
"If your half-back can't pass the ball, then there's something wrong with the game. You're looking to pass and all you see is one of their players.
"We lost the ruck from the game and when you lose a primary contest from the game it changes the game considerably and it ceases to become rugby.
"If you paid for your ticket, ask for your money back. I'll have to give my money back to Ian Ritchie, because no one's had rugby yet.
"I don't want to be involved in those sort of games. I'd rather go home, pick up my stumps, put them in the kit bag and go home.
"If you think that's smart, fantastic. I don't think it's smart rugby."
It took until the second half - after a talking to from Jones - for England to adjust and assert themselves.
Jones added: "Could we have adjusted even quicker? Possibly, but it's difficult. The referee (Romain Poite) got flustered as well.
"I'm not critical of our side at all, because we didn't play rugby.
"We probably got flustered a little bit by their tactics, which is normal.
"It ceased to be a game of rugby. We practised for a game of rugby all week and we didn't get it."
Jones also began the mind games with Scotland, England's next opponents who visit for the Calcutta Cup on March 11.
He added: "If you said where we wanted to be at the end of three rounds, we're exactly there. We're undefeated, we've got a bonus point.
"We're looking forward to Scotland coming down. They're talking big already, they're on a roll, they're confident, but they've got to carry round the expectations now for the whole Scotland nation for the next two weeks before they come down and play us.
"They've got to handle that, which is going to be interesting for them."