Invest in the manufacturers, not sell to the end users
The problem is people don't know or really care why they need digital radio in their lives. Their cars don't have it so why should their alarm clock or kitchen radio have it?
Instead of pushing it down consumer's throats with marketing or scare tactics, the government should invest in the manufacturers of the devices to get them to wind down the production of analogue in favour of cheaper digital devices.
Once people start buying them it will soon become the norm to just tune into a DAB broadcast.