Data and airtime dissappearing

Recently ported my number to Vodacom on the 05/10/2015 and loaded 1gig of data that vanished overnight without me having used it. called call centre and they took me in circles, then headed to Vodashop where I was assisted by technician who verified that all was well with my phone. I bought 100mb to test and it was gone in literally 2mins, investigation was made and I was reimbursed with my data that worked well till today. loaded 1gig of data this morning and within 10minz it was depleted without me using it. I'm extremely frustrated as I use my phone for work and it is dysfunctional because everything I load disappears. please rectify this problem ASAP cause I cannot function like this.