how to cancel ATT ipad data plan wtihout ipad

[joezhu110]

i have 2gb att data monthly plan .but i sold my 3g ipad so now i am using ipad sim card on iphone .so does anyone know how to cancel it without ipad 3g
or it would automatic cancel or i must use ipad 3g to cancel it ?help please

 

[Mitchrapp]

I always thought calling was the best way.