I am 0-2 in adding UDP at the Apple store without having purchased online prior. Both times that I have walked into a store and tried to purchase and choose UDP when adding a line, the option has not appeared on the handheld that the Apple reps use so I have abandoned both transactions (no I didnt run out of the store, just told them I wasnt interested if I couldnt have unlimited data).
Any idea why I cant choose the UDP option in store but have no problem using the same number(s) online and choosing UDP. The inventory in SOCAL is dry and the only option for scoring a phone the past couple of days has been in store not online.
You need to have it set up as a family plan to use in store. When picking plan, choose your family plan, then unlimited data.