Query taking to long

I was on a cell C contract. It expired last year and i had to renew it. I renewed my contract to the 2GB for R99. I specifically wanted the top up package like i use to have where you pay R99 per month and get 2GB of data and once your data is finished you get cut off. When receiving my bill on the 12/01/2015 i noticed an absorbent charge on my statement. I then phoned on the 13/01/2015 and logged a complaint about my bill and was then told i have an open line contract with a R15000 limit. How stupid can cell C be i don't even earn close to that a month so why on this earth will i take such a high limit or a contract like that, I never wanted a contract more than the 2GB as most months i don't even finish it. I then phoned on the 21/01/2015 and they said they are still investigating and finding the recording. I then phoned again on the 27/01/2015 and was told the same thing. I am highly upset as i was told this will be sorted out in 2 - 3 working days not 2 - 3 weeks.