That's the weirdest thing I've ever heard. If the government can't deliver on promises, that's nothing to do with the media.
I'll leave these here for you ...
Seems like things will be better off if the UK is not handing over billions to the EU.
Government sources said the increases, which would be paid for in part by a “Brexit dividend”, would amount to around £600m a week extra for the NHS in cash terms within six years.
https://www.theguardian.com/society/2018/jun/16/may-to-unveil-20-billion-pound-a-year-nhs-boost
https://www.spectator.co.uk/2018/05/350-million-for-the-nhs-how-the-brexit-bus-pledge-is-coming-true/
Personally, I think "how much money can be spent on the NHS" is the wrong discussion. It should be about medical care, not how much budget can be pissed away because we know how government budgets work and it isn't about being efficient or rewarding good decisions. You could spend all the GDP you have on the NHS and they'd still want more.