INCORRECT BILLING ON A DATA ONLY LINE

This is the final time I am going to call Vodacom to resolve an issue aroung incorrect billing for call line identification on a data only contract. This has been ongoing from when I changed a number from a cell line to data only. The references I have for logging a service request since 25th June until today this is NOT resolved. I received a sms advising that as an goodwill gesture I would be credited with R208.56 and the call line identification would be deactivated, which it was. I however will not accept the credit as the amount is incorrect. The billing department needs to go back from when this data only contract commenced. I have the following reference numbers for this query 25/6 (***), 26/5 (***) and this morning 30/6 (***) I expect Vodacom billing department to investigate this matter correctly and credit my account with the full amount including VAT as that is what I overpaid. Do your job Vodacom. I am tired of being shunted from pillar to post around this issue.