Vodacom is so pathetic!

I am now struggeling from end of November to cancel three lines at Vodacom. What a impossible mission. Up until now nothing was done, I phone hunderd of times but nothing was done. I spoke to Vodacom via facebook messenger then two lines was cancelled but still one line is active and now my account is in arrears because of this lines that was not cancelled in time. I really do not now what to do to get this sorted, Really it is not supposed to be this difficult to cancel a line!!!