Engine light on Fiesta

Hi,

I took my ford to 24motors for 60000 Service and my car came back with engine light I reported it and they said I can take it to any dealer,

then I took it to motomid Middelburg,

they reset the engine light but engine light came back on. Then I took it back to 24motors and they say they cannot do anything because the light will come back on but I must bring it back, ayyy then I booked my car with motomid , and they told me that they going to reset the light again, they did and light came

back on. Then I took it to motomid on the 12th and I was sure my car was going to be fixed as they promise (Service advisor Mavis) but I got my car still on the same condition, then Mavis told me to bring it the next day. I did but Mavis said it was a misunderstanding I was not supposed to bring the car on that day 13th . I am not happy about ford hence could you please fix this ASAP . Last week, the oxygen sensor was replaced and it came back same day when I took the car, Now I was at Motomid and they said they don't have a courtesy car for me which is a big problem for me and I must drive my car when it's TOO RICH on fuel please help URGENT with a courtesy car, I WILL NEVER recommend for to anyone am driving the ford fiesta titanium Eco boost 1.0.