My Impala had 35000 miles on it, The FIRST time. At 75000 miles -again. on 2008 Chevrolet Impala SS

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
2nd time cost me 300.00 at dealer. Now have 78000 miles, and warning lights come on intermittently, sometimes 2 or 3 times a day. Not sure what to do...notified dealer at last oil change, but could find no EVIDENCE of malfunction, so nothing done. They also refused to correct problem under warranty. The car has 100,000 mile powertrain warranty still effective. Is it normal to have failures on the throttle body every 35-40000 miles???
(1) Answer
What is your question about? What warning lights come on? What were the codes? What the heck did the dealer charge you $300.00 for? To look at it?