Depending on the type of infection, it can take 2 weeks to 3 weeks to clear up. I'd keep putting the CS several times a day in the eye and take it internally if you've got enough on hand to do so. Oregano oil internally would be a good alternative. You can get the oil or capsules. It would be more convenient to knock back capsules. I'd take those daily until your eye is better.
I've had really bad eye infections that took 3 weeks to clear and mild ones that were better in 4. It really depends on what type of bacteria you have. If it's not clearing up, maybe you've got the wrong kind of drops.
But seriously, increase the frequency of the cs drops and throw some oregano oil into the mix (internally -- swallow) and it should take care of it.