2021 GENESIS G90 Tires Problems

This is not about a tire failure but rather dangerous mis sizing of tires from factory.I bought the car new. It was never in an accident or had a flat tire and did not have service call until this week at 13000 or so miles.the service included tire rotation and balance, but the service man called and said he wasn’t going to do it because the driver rear tire was the wrong size!!!! It was supposed to be 275/40 R19 101W but was 245/45R19 98W. The two front tires are 245’s as they should be but BOTH rears are supposed to be the 275’s! Clearly this affects handling, wear, stability etc. I’m a very careful driver but someone less careful could roll over on a fast corner turn! How many more Hyundai/ Genesis tires are mis sized? No one checks that when you buy a car!