I called to book an oil change because my oil is a...

I called to book an oil change because my oil is at 30% and they advise me to wait till my light turned on! Never in my life have I waited till my service lights turn on to get my car serviced. Apparently it's a new policy not to service vehicles until their service lights turn on? Which is ridiculous, you shouldn't have to wait till your car is in dying need of a service before you can get it done.