Breach of Contract - No Accountability

Signed 2-year data contract at R149 pm with Vodacom 4 years ago, capped 5G day &amp; 5G nightowl.Just before expiry, got call from Vodocam to renew at cheaper rate, no docs needed ,as conversation was recorded.Everything went well until 14/03/16 got a bill for R2294 &amp; since then have been trying to sort this as they breached the contract by uncapping.Huge amount of time/phone billing wasted, spoke to Billy, Mokgadi, Myito, Sicelo, Norma, Vuyo,Princess, ,Khanyi, Nkatlego, Heyman, Nareen,Tebho,Paul, Franci, Lungelo, Nozipo, Tabiso, Nomfundo,<div>Nompumelo, Kosi,Wayne,Irene &amp; others who refused to give names/cut me off.Advised they upgraded their system, my contract changed unknowingly. Impossible to speak to anybody with authority. Told not to worry about letters because it was auto-genterated until resolved.Received invoice on 14/04 for additional R1678. Yesterday received letter to pay R3974 in 7 days or be recorded in the credit bureau. No response to tel.no. on letter. Told by Irene that when the contract was renewed, it was for 2 gigs and uncapped. I advised them to go back on recording as this was not mentioned to me. Told me somebody will call me.Still no reply to tel no. on letter. </div>