I really don't know anything about cars, so I'm going to try and explain what is going on with it as un-confusing as possible.

I have a 98 Pontiac Grand Prix that has this section inside that marks the "oil life" of the car. Right now it says "oil life 49%".

The first time it marked 53% I went to get oil change and afterwards it marked 100%. This second time I went to get oil change the 53% didn't go up to 100% instead it's been slowly going down.

The first thing I assumed was that when I went to get oil change the second time they probably didn't do anything, so I checked the oil myself. Or so I thought I did. I pulled the little stick that says "engine oil" cleaned it with a paper towel, put it back inside, took it out and it marked right on "full." What's wrong than? If there is oil why does my car keep marking 49% and keeps going lower. Is that dangerous?

I'm a confused girl.

GM products, possibly yours do have a life indicator. The indicator is supposed to be reset by a scan tool or believe it or not (The factory installed radio allows you to set lots of options for the car). Reseting the oil indicator to how long the headlights stay on can be set with the radio.

Oil life is complex. The least life happens when the car takes short trips and never gets really warm. Long trips give the best life.

Oil LIFE and LEVEL are two different things.

The lifetime indicator may not have been reset at the last oil change.

I totally agree with kiss. A simple reset needs performed. You paid for a service, and the service was not 100% completed. Now go back and tell them exactly what you told us. That's as simple as I can put it too. :)

Yup your service tech didn't reset your oil life indicfator aftertheychangedyouroil but it is real simple to do. But anywy take it back to them because someone is being careless