Hi,
Usually there are many compatible head units that work with Maruti stock steering controls.
There are two possibilities.
1 Your HU is completely incompatible.
2. The installation shop missed something.
Go give them a visit and enquire...
Are you from Nilambur?
Post some pics of your car in Nilambur.. The scenic places are great for the heart and eye...
Thnkx
Anoop CH