I would like to extend my s2 visa for 4 more days,my daughter who is a student here.

Will be writing her exams on the 26th and my visa expires on the 23rd, but I have a 3 month visa with a duration of 30 days and I woul wish to stay the extra 3 days.please advice me urgently as I have my flights booked for the 27th at 1.25a.m.
Thank You