Austerity Hasn't Worked, So Why Persevere With It?

During the election campaign, the Conservatives often made the claim that austerity was working and was needed to bring down the debt.
The answer was they said that their strict measures would clear the debt by 2015 which was then pushed back to 2019 and has now been pushed back again to 2025.
Now austerity is back in the news because the Government are contemplating easing the measures after 7 years of cuts and closures so how much has the measures reduced the debt by?
In 2010, the Great British debt was £845 billion and after 7 years of cuts and austere measures, the debt now stands at £1.6 trillion at the end of July 2016.
So the question is in which way has the Government measures reduced the debt because whichever way you want to spin it, the debt has doubled.
The previous double act of David Cameron and George Osborne and then Theresa May made sure the debate was always about how only they could be trusted to balance the books, or live within our means as the phrase went, but now the cat is out the bag and the hardline austerity since 2010, where everything that could be cut was slashed to the bone, hasn't worked.
We found out the hard way that it was a terrible idea to cut police numbers during the terrorists attacks, the council cuts when the tower block went up in flames, devastating underfunding of the NHS when winter rolls around, closure of Homeless shelters when the city centres shop doorways fill up with the homeless and the 33% rise in suicides amongst benefit claimants who have had their benefits cut.
Austerity hasn't worked and it is hard to believe that the Government has only just worked that out now so we should be asking why was it persevered with and was the Government incompetent or just being ideologically malevolent?