Hatchback is ajar if closed without slamming

I bought my car after it had been in a minor rear end collision. The bumper was replaced. You have slam the hatchback or the ajar beep will come on. I looked at the latch and there is no adjustment in the bottom latch that is held on with 3 bolts. Is there adjustment in the top part that is on the hatchback. How do I adjust this to eliminate the hatchback ajar problem?