2 new tyres bought from ATU. DOT from 2002 , now what?

Hello! last week I bought 2 new tyres (UNIROYAL 225/60 R 15 96W RALLY 540) from ATU and had them re-edited there. Today I look at the DOT No. and see that the tyres from the year 2002 are. So the tyres are about 5 years old. Was today at ATU and asked if this is normal tires from 2002 to sell without giving the slightest indication of the age. Well, the employee said that he would personally drive only such tyres and I should not worry about The tires are new and not used yet. Therefore the age does not matter. I am not afraid because of the safety of the tires but nevertheless I find that one should at least give a hint with 5 years old tires. If I had known that the tires are 5 years old, I would not have bought them. I will never buy tires at ATU again and will never enter these workshops again. My question is if someone knows if you can take action against them and if you want to do so. How old can tires be max. the dealer be allowed to sell them as new? Greetings, Willi