Unacceptable Service

My husband Achmat Fareed Khan purchased a new Datsun Go at Imperial Datsun/Nissan Parow on 16/01/2015. Policy no: ********** Transaction ID: 772265 Service Plan start date: 16/01/2015 The vehicle was purchased with a 3 year warranty plan and service plan. I delivered the vehicle at Nissan Parow for the 45000km/3 year service today, Monday 15/01/2018. I also told the gentleman who booked the vehicle in that the engine made an unusual noice since the weekend, the first thing he confirmed was the maintenance which I understand is different to the warrantee the company offers. My husband was phoned about an hour ago by one of the mechanics who advised that the warrantee had expired two days ago (13/01/2018) and that the noise on the engine will not be repaired unless we pay for it ourselves. According to my understanding if something is purchased on a particular date and has a warrantee/ gaurantee it has to expire on the exact date 2/3/5 years later. If our vehicles was purchased on the 16/01/2015 and our maintenance plan expires on the 16/01/2018 why were we told our warrantee expired 2 days prior to the purchased date? I went through all documents received on the 16/01/2015 and non of it has an expiry date of 13/01/2018. I refuse to pay for any mechanical work that's supposed to be covered by warrantee.