Car dealership

I bought a car on 17 december 2017 with a mechanical warranty, and now that we want to use the mechanical warranty, the dealership is saying that they don't have any proof of purchase for the warranty. Now I have given them proof of the warranty paper that was sent to and I even have a bank statement that said I paid for the car and the warranty I even have corresponding emails that I sent to the sales man sending him documents for the warranty and all the dealership can say is that their systems crashed. Can you please help me