Forced to pay diaper fee

My son’s days care is staring a new program where for $15 more per week, you can get included diapers and wipes. I am going to confirm with the director but from what I gather, this is not optional. I’m very annoyed because, one, the diapers are terrible and cheap and also don’t fit my son correctly, (they gave us a sample) and two, when I did the math, it’s far more expensive for this program than if I bought them on my own (I get them in bulk at a store similar to Costco). What are my rights here? Does anyone have a similar program at their daycare? I’m a bit annoyed to have to pay an extra $780 a year for a service I adamantly do not want.