Vodacom Wi Fi Contract

I have a R99.00 Wi Fi contract with vodacom. They increase my contract without my knowledge. I phone them and ask thats going on they told me that I did subscribe to Opera Telecomm, phone number ***. I phone already several times and leave messages but I did'nt hear anything. Will you please get my money back from them. The details is as follow: From 04/2014 - 09/2014 they charge me R129.00. 10/2014 - RR130.60. 11/2014 and 12/2014 - R129.00, 01/2015 - R188.51, 02/2015 - R334.88 and till today my account is R245.67. This is my Internet and it is impossible to subscribe to anything, because I only use it for internet. Will you please help me. I want all my money back please. The number for my wi fi is ***.