Vodacom ******** their own

Hi guys, my phone number was recently deleted on the network because of outstanding arrears I has with vodacom. My initial contract instalments with vodacom was more than doubled without my concern. They told me that because I purchased a black Friday promotion my installment was more than double then but they fail to inform me of any changes in my contract. Now they are saying I have less than a month to pay up or my number will be lost forever and I will be put to ITC. Can I take them to NCA? Please assist