I don't understand how they're paying $2000 a month to AT&T. We have 5 iPhones and 1 AT&T iPad on a family plan with unlimited text and very high number of minu

I don't understand how they're paying $2000 a month to AT&T. We have 5 iPhones and 1 AT&T iPad on a family plan with unlimited text and very high number of minutes (can't remember exactly) and pay not more than $450.