I'm not one to get 'shouty' but I think the days of automatic deductions from
salary without warning should be over
I thought they were. Do we not get the warning through the term 'Overissue', whereby you will get a deduction from pay of figue£x that is offset by the same amount paid into the left hand column. You should see this during the month before they will actually take the money off you. This gives you notice that for the following month you will once more get the deduction of figure £x but without the overissue to balance it out.
At least, I think that is how it works.