False advertising and poor service

I bought a cellphone from Hi-Fi Corp Southgate on the 20th July 2019, as per the advert I am supposed to get 800mb of data monthly for 12 months. To date still no data allocation, been to the store numerous times and no one is able to assist. False adverting, why advertise something you cannot offer the customer. Phoned Vodacom also numerous times and they are also not able to assist. Disgusting service