My data vanished

i had about +300MB and earlier on this morning i received and sms telling me i have 50mb left and within that hour i received another sms saying i have 7mb left... and when i contact your call centre they cant tell me what happened to my data. instead i got put through different department.. and i was toldfto call *** and the gentlemen who answered could help he pit me through to technical departme depant and a rude lady answered and pretended she dont hear me and she dropped my call. and Cell c can you please bring back my data.