Simply go into settings, click on data usage, and then you can see how much you've used each month, set limits, and enable alerts.
Naanị ịbanye na ntọala, pịa data iji, mgbe ahụ, ị nwere ike ịhụ ọtụtụ ị jirila ọnwa ọ bụla, dozie ókè, ma mee ka alerts.