2004 Dodge Neon RPM increases when I press brakes

Hi,

I have a 2004 Dodge Neon which was just serviced by the dealer. Since I got it back, the rpm increases by about 200-500 revs when I press the brakes to stop. So say RPM at 1200 when I press brakes, then RPM goes up to 1500-1700 even though I didn't press the accelerator, then I press brake a couple times to stop and RPM goes back to 900.

This does not happen when the engine is cold, happens only when engine temperature reaches normal.