Awful Coke

I bought a Coke from a vending machine and and it tasted really awful like it might have expired. I checked the expiry date and it was meant to expire later this year. I immediately tried looking for customer service details on the can but there were none. I tried searching the internet then finally went to Twitter. Spoke for Coke Africa and they referred me to Coke ZA but I could not private message them so I posted a screen shot in hopes for a response but there was none. I'm genuinely disappointed as loyal customer to the brand that this has not been resolved.