Is 'EXEMPT EMPLOYEE' the equivalent of ' ROCK and a HARD SPOT???

Is it legal for an exempt employee to work 40+ physical hours in a week, and still be docked for 'benefit time' (sick, vacation)? Example-

Mon: 10 hours worked

Tues: 10 hours worked

Wed: out of office-personal time called in

Thurs: 8 hours worked

Fri: 10 hours worked

Sat: 4 hours worked (Saturday ends the pay period for payroll purposes)

Total PHYSICAL hours in the office: 42 in the same work week

MY Position: I get paid for 40 hours only as an exempt employee by common acceptance of the 40 hour work week. (if i'm ALREADY wrong--just tell me now and let me cope lol) So by Saturday, I've already worked 2 hours for free. So by deducting 8 hours from my accrued (read: EARNED by YEARS of working) /BENEFIT time, I'm technically having my pay REDUCED by a full day. Yes? No?

QUESTION: Can my employer still force me to use 8 hours of accrued 'benefit time' for the 8 hour shift missed on Wednesday if I am a regular EXEMPT fulltime employee?

QUESTION 2 (just came to me--be patient with my deficient attention span) can an employer mandate overtime-and if so, must notice be provided or discplinary action taken for failure to work said mandated OT?