Ann: Update - Notification of buy-back - ICI, page-58

can someone please explain what happens to the bought back shares?
like when are they cancelled? i thought shares bought back were immediately cancelled, but looking into the number of shares on issue, it appears to be remaining static. see here:

screenshot from ASX's website 2nd August showing SOI @ 1,268,756,056

between 2nd August (above screenshot) & yesterday, there were four buy-back announcements:

2nd August: 1m bought
5th August: 450k bought

8th August: 800k bought

9th August: 2.6m bought

Total bought: 4.85m

so by my calculation, SOI should have reduced to 1,263,906,056; but ASX shows SOI is unchanged @ 1,268,756,056?

(above screenshot taken today)

i know nothing is wrong, i only want to learn more about how SBB works;

also, i cannot find reference that the previously 35m shares that were bought back were cancelled; does anyone know where to find the information, like a data source that displays the changes in a company's SOI movements over time?

maybe @BigWill2018 or @Surandy70 can help me?