Terrible after sale experience- Promises arent kept

I recently bought a car from Motus- Toyota Bedfordview in June, they happened to have some promotion running that offered a cashback incentive. To date, I have not received that money and I have been following up with the salesman- Johanny who facilitated the purchase of the vehicle. I never get any communication from him about the delay, I literally have to call them all the time. I recently contacted the principal dealer- Desiree who said she would look into the matter and call me back to provide feedback. I'm still waiting to get a call back from her, I have emailed her and she still hasn't rep**** to my emails. This has been a terrible experience and I would never recommend Motus to anyone because the after-sale experience is beyond pathetic.