You can't quote the net figure when we can't control how the money coming back is spent. If the EU spaffs that up a wall on farmers and other such nonsense then it's no good to us.The net contribution the UK paid to the EU in 2016 was £8.6b
We - tax payers - are paying £40b a year in interest on government borrowing. Today a Tory government announced it will be borrowing more.
If the Brexit vote had not happened the economy would have powered out of this debt. We saw a few gdp % points less growth primarily because of the brexit vote result.