Why is it so difficult to get a response?

I recently bought a shotgun microphone through Takealot. The item is GREAT, but the after-service from Takealot has been pathetic. I requested an Invoice update, as the invoice I received did not include all the info SARS needs to do a VAT refund. THREE weeks later, email upon email and ticket upon ticket - but NO help! I received emails saying the ticket is now closed????? What more can I do?