Miss leading Information and Bullying of customer

I took my vehicle to action ford Roodeporte, to assess the car in August 2017 when the Kilometres on the car was about 89 800 as expected( The engine was smoking and a constant smell of diesel was present) I was told that the repairs would be covered by warranty, however unfortunately I did not have the service book in my possession at that particular time the repair centre advise me I should simply bring the vehicle back when I have the service book and had assured me that the repairs would be covered by warranty. I then took the vehicle back with the service book at a later date. When they booked in the vehicle for the second time It took them 3weeks just to diagnose the same fault on the vehicle that they were already aware about. A few days after that they called me and said I will be liable for the repair cost. When inquired what was the reason they said it was because I have not done a 90 000-kilometre service, I explained to them that they where aware of the problem before the service was due as well as the service only being 500km over due. They completely rejected my request and have not communicated with since.