It does not say that that sum is sent to the EU. The abatement is applied before payment, as an instant discount. Though I am thrilled to see that you can read section headings, I would've been happier if you understood the entries under those headings. Extremely dismayed at the thought that your political leaders, rather than being shameless liars, might simply be sloppy and lazy readers like you.
The explainer in 2018 addressed the lie from 2016, but what was true in 2018 wrt the way the rebate worked was also true when the lie about the payments was told in 2016—which is why the same explanation was given in the FullFact article about that lie that was published in 2016, prior to the referendum itself. You have been referred to that article previously, so you must know of its existence. But, if you had forgotten, here it is:
https://fullfact.org/europe/membership-fee-eu/