Non Response by Ford SA

Good day

I drive a 2016 Ford Fiesta Titanium.

I have had a re-occurring engine light problem in my vehicle since May 2016, which also affects the start stop from not functioning.

In September 2017 my vehicle was at a local dealer for a whole month .

The problem arose again in March this year , they put injector fuel & the car was fine for a few weeks.

Now I have been driving my vehicle with the engine light on.

How can it be possible that that they cannot figure out if it's my vehicle that has this problem or do other customers have the same problem if they driving the Fiesta Titanium??

They have had problems with Kugas that were re-called. Why don't they take it back & offer me something else?