Is any airline actually meeting the 7 days? Nope. Is any regulator punishing airlines for failing? Nope.
The US DoT is toothless. It took them 5 weeks to even respond to my complaint about AA and that was a 'we are now looking at it' response. In the meantime AA had refunded me well before the DoT contacted them.
It's taking credit card providers weeks and weeks to even start looking at chargebacks as well. Again it took mine over a month to even take a first look into it nevermind sending it to the airline (Finnair) in which time they had actually paid me back my cash.