International Travel Vaccinations hospital/clinic
I just phoned up Pusan National University Hospital, which is one stop after Jalgachi on line 1. They have a foreigner service there. It may be at a higher cost, but then again you have the convenience of someone speaking English.
Link to webpage with phone numbers http://18.104.22.168/coding/eng3/main11.html
Just got Hep A and B done today, which cost a 100 bucks + 38 bucks for consultations, which may or may not have included the rather nice lady called nurse Lee who had fantastic English and walked you around all the processes.
Unfortunately they didn't have Malarone malaria tablets, only Larium, which I took once before and felt so sick I took the risk and abandoned them.
The Good Gang An near Gwangan beach (Geumnyeonsan subway) does have Malarone though and also injections. Although my friend said her Hep B cost 70 there.
Wouldn't waste my 4500 KRW on something that you would hardly get.