The ASA is the most worthless toothless watchdog there is. It doesn't even bloody bark any more, just grumble in its sleep.
How hard is it to say "Any new advert from today must comply with this statement, and any existing print/billboard/bus advert must be replaced by the end of next month. Anyone failing to comply with be taken to court by us."
I know, I know, it's not in the ASA's remit, but what the hell is the point of it if it doesn't have those sorts of powers as an absolute minimum?