Promised free data, but not received.

I upgradred my cell contract at the end of August via Vodacom call centre. The agent told me as a longstanding customer of 20 years they are giving me 2Gb data per month. To date I have not received it. It is billed on my invoice at no charge. I have sent emails and left messages, but nobody calls me back. Staff at the Vodashops say they can't help as I didn't upgrade through them. Awesome way to treat your longstanding customers - not.