Non-existent service!

On 31 May 2020 I bought a fitness device from Sportsmans Warehouse. As I am on healthygear, I am supposed to get a 30% cashback. Despite various calls and emails I still have not received it. The last time I called on 3 Aug, the consultant Jacques promised me he will escalate it to management and said my query would be resolved within 72 hours. No such thing! I still have not received any feedback from Discovery Bank. The lack of service is a disgrace!