Vodacom is *****ing my money

In April 2015 I paid my outstanding balance on my Vodacom contract and ported my number to Cell C<br> Every month since then Vodacom have been debiting my account for R1294.07 every month . Each month I phone - I explain my long story - I get a reference number and I am promised it's all sorted out - only I have to go through the same thing every month ! there appears to be two numbers on the invoice - one is mine but the other ? Well nobody really knows . One call told me it was a Nashua mobile number - so I called Nashua mobile and they say the number doesn't exist . Slaap tiger ? The only slaap tiger in this scenario would be Vodacom !!!!!