Who can you Believe

Natasha from Mondo Mobile phoned me on the 20th selling me a 3Gb Data Top up Contract with WiFi Router for 24mth. I accepted. Ref No: ***4. I received my package on 24th Aug 2015. Received an sms from Vodacom confirming my contract, but with a sentence stating \ Your credit limit is now R14150.00."I phoned Vodacom today & they told me that it is an open contract therefor the mentioned limit & with night owl etcetera. This was not what was agreed upon when I have spoken to Natasha! I phoned Mondo Mobile and was not allowed to speak to Natasha as she is only to make outgoing calls. The lady who took my call (Bvisha) said she will investigate and revert back to me. I asked the lady to specifically listen to the recording as I specifically asked / confirmed a few times that it was a top-up and also that I was not informed of Night owl etcetera. Vodacom gave all my details to Mondo (She told me exactly what amounts I was paying when) to \""help\"" me with managing my account / data better. How is that possible if they give you an open account with a limit of R14"