Incomplete online order

Vodacom's call center is useless. I purchased two devices in April online, I was told I will receive an Azoomee 12 months subscription voucher of which I never did on the day I received the two devices. I then phoned Vodacom to log a query I was then told to e-mail my query to after being transferred back and forth to the Online and After Sales Department and that was on the 13th May until now I haven't received valuable response except for the acknowledgment of my email. On the 03 June I received a tax invoice with the azoome voucher description written on the tax invoice and there was no voucher on the package. Today I am calling again to find out about the tax invoice, agents from the Online department transfer me to After sales department. The after sales agents transfer me to back to the online department as both these departments cannot assist me that's my experience when I call Vodacom