How can I get the most out of my bikini wax and prevent re-growth three days after my appointment?

Okay, so I realize this question might cross the line into “TMI” territory, but basically I’m really frustrated and wondering if anyone else has had similar experiences and/or suggestions.

I pay like $30 for a full bikini wax. I’ve paid more before and had the same results so I don’t think this is my waxer’s fault. No matter how long I “let it go” before my wax, it never stays completely bald for more than a couple days before new hairs start sprouting up. I want to get my money’s worth! Is there any way to “train” all the hair to grow in at the same time so that it can all be waxed at one time and grow in again at the same time? I haven’t waxed any other body parts (legs, eyebrows, arms), but do you have the same experiences? Thanks!