No Response from Vodacom

I am a very upset R20 000 a month customer . I have many credit notes outstanding on my account with reference numbers but nothing seems to be credited and no one can answer why . I have been sent an email by a person called Judy Chetty that a credit note has been generated and it will reflect on my account in The middle of March , we are now at the end of April and still no credit reflecting on my account. I have sent numerous emails to Judy Chetty and guess what she never replies or responds . I have even been to the Vodacom store at Liberty Midlands Mall but still no joy . I need help urgently on this matter. Contact Number is : ********** 766.