Q: My car wont start, ECM issue

We procure this Suzuki Sedan SX4,2008, Automatic from a car company in Nigeria called C & I motors in 2009. the car had an head on accident with a learner, which affected the radiator and this car company couldn't support us, that a friend had to order the replacement radiator double cell for us.. since then we have been suffering on the car on over heating because our region is really a tropical one ,2015 we took the vehicle to a long distance and burn the gasket from the over heating and i got a technician around to have it replaced and since then the vehicle had been worse in performance, so we abandoned it in the house, and just last august we decided to give a mechanic who repair the engine well, but all the warning indicator came on which the mechanic said we may need to clear it with a programmer, and i also notice the Air conditioner not working, which i gave to an Auto HVAC technician, who made the ECM to be faulty. how can you help to get it started.
My car has an automatic transmission.