unable to purchase xfinity home cameras with bulk apartment plan

i have xfinity through a bulk plan with my apartment complex, and i’m trying to purchase additional xfinity home cameras and equipment. every time i try to buy them through my account, i get an error saying there is a problem and it will not let me continue.

i’m just trying to find out whether customers on bulk apartment plans are allowed to purchase additional xfinity home devices and, if so, how i can complete the purchase.