Quite common. Does not necessarily mean the tyres are over age. Suggest you first refer it to the dealer who sold you the car. If the dealer does not replace the tyres, write to the dealer principal stating that you believe the tyres on the car he sold you to be sub-standard and unsafe and state that you will be having the professionally examined.

Send this letter by post office special delivery and keep the certificate of posting clipped to a copy so it becomes a matter of record. Then take photos of the tyres and refer them to Dunlop. No help there, have the tyres inspected by Scotia Vehicle Inspections. Depending on the results, take the matter further.