6 months and still no refund!

Contract:I ********** , Ref: ********** ********** and ********** ********** 7. AMOUNT:R377.00 Since 07 April 2017 I have been phoning Vodacom to get this amount refunded because it was initially overcharged. I have lost count on how many times I called, I spoke to all departments, even sent an email to ********** with banking details... and every time the consultant says that it will be done in 5 working days. Sometimes they don't see anything on the system, after I insist they acknowledge and say they will transfer or refer me to the accounts department. They have all my contacts: landline, cell, email, but still nothing has been done. I told them to credit it into my new contract:I ********** -011. At times I have spent over an hour on the phone and still without any resolution. Really, do I have to come here to expose this!?