Data Usage

Data Usage from Telkom is not accurate! On data top ups, 10G can last 10 days and the next top up it lasts 1 day??? For the same amount of work done by a single person!! How does that happen??? Plus, when going into the Telkom branch to sort this matter out, when they pulled my Customer Profile up with the number for the data usage, there was my profile PLUS another user profile on MY number?? Telkom..... WHY and how is there a second user on MY number?! This must explain how the data can get used up so fast?! I have the photo of the "customer list" with my profile and the second user attached to my number. Assistants in the shop were not helpful with this matter at all! Telkom always has excuses and makes paying customers wait with no answers! Who can fix this issue??!