Buy one burger and get one free on Mondays | Spur
There's no mention on how long this will run. I found it at Picodi which says it's ongoing.
The link says:
Buy any Burger or Hot Diggity Dog from the Spur Adult Main Menu, and get a single burger or Hot Diggity Dog free.
Add R20 for a free double burger. Not available as a takeaway. Only valid for Burgers and Hot Diggity Dogs ordered from the Adult Main Menu. Available Mondays. Terms and conditions apply.