I'm quite surprised to be honest that someone would poorly 'remap/chip' a 2004 GT
It's possible that what you have is a 'Piggy back' chip which is plugged into the ECU and then hooked up to the car.
Although, even the simplest of Alfa dealers/mechanics should be able to rectify this for you within the space of a day so I can't see why it's taking so long for you to get this annoyance rectified,
One thing's for sure though, you need to get it sorted ASAP and back to factory standard.
Then you can start to really enjoy Alfa ownership
Welcome aboard!