2003 Chevy Malibu

The repairs that have been done to date are as follows: new heads, replaced rocker armes, replaced map, air flow, and a third sensor but I don't know the name of it andc replaced head gaskets. It was put on the computer to see if any codes came up and none did. We do not have any warning lights on. When we started the car engine would go up to 7000 rpms or higher. After the work was done it did get better now it goes up to 2500-3000 rpms when you start it up, however the longer the car is running and the hotter the engine gets the higher the rpms go when you stop at a stop sign or put the car in park or neutral when the car starts moving or puy in gear the rpms drop. I found where the 2003 Malibu is under recall for a problem simuliar to this but after talking to GM they inform me that according to the vin number this specific 2003 Malibu is not covered under the recall. But I can't help but wonder if they may be mistaken. We have had three ASE certified mechanics look at or work on this car and some $2000 later we have three mechanics scratching their heads, and empty bank account, no answers, and a car that still is not running properly!