Disappearing data

Hi there I have a data issue with MTN. My number is: ***.

I have WI-FI at home so I never use my data when I'm at home - I basically only use it when I'm at work. So yesterday I had 1.29Gb (received 1Gb as part of my recurring bundle) in no time it dropped to 117Mb. I had no applications or downloads running in the background & all my updates are set to work on a Wi-Fi connection only.

I emailed them yesterday morning (***) & they responded with a general email asking security questions (this just further delays the whole process). Anyway, I rep**** to that email at 10:03 yesterday morning but I have not received any response or even an acknowledgment of my email as yet.

I want this matter resolved ASAP as there is no way I would have used 1Gb in less than 10 minutes! Kind Regards,