Incorrect billing and breach of contract

I signed a contract with Telkom for the amount of R599 on Uncapped Wireless Broadband that was advertised on their website. My SIM was only activated more or less on the 9th of December 2015. I received my invoice for the amount of R1394.57. This is the breakdown of the amount: 1 x SmartBroadband Uncapped Wireless 2 + Huawei B315 + Antenn... R 1,394.57 Wireless Activation Fee R 200.00 Deal Discount Wirelss Activation Fee R 200.00 Cr Add on Device Installment Fee RC base (01 December 2015 -31 December 2015 ) R 74.00 CLI Presentation (02 December 2015 -31 December 2015 ) R 8.23 Uncapped Wireless Broadband 2 (02 December 2015 -31 December 2015 ) R 604.84 CLI Presentation (01 January 2016 -31 January 2016 ) R 8.50 Add on Device Installment Fee RC base (01 January 2016 -31 January 2016 ) R 74.00 Uncapped Wireless Broadband 2 (01 January 2016 -31 January 2016 ) R 625.00 Total R 1,394.57 Subtotal (Recurring Monthly Fees) VAT included at 14% R 1,394.57. Why am I paying for January already? Why I'm I paying for Device Installment Fee? Why I'm I paying a CLI Presentation of R8.50? This was not stated in my contract I signed? I should only be paying R599.00, this is a breach in my contract.