Windhoek Beer - No response to "contact us" (Empty 330ml Beer Can)

Bought a 6 pack of Windhoek Lager 330ml, 1 of the beers is totally sealed and unopened, but the can is empty. Not impressed by this. Explanation, please.

Have the can as proof, the serial number is 6 009801 472898.

Logged message on web twice no response - https://windhoekbeer.com/contact-us/