Empty "full" cans .....a packaging problem?

Just wrote another similar review on schweppes. What is it about getting six packs of empty or half empty cans of Tonic water? They clearly use the same packaging company and clearly something is not right! To their credit both have replaced defective products but I've just ended up with empty cans from both again.

And a gripe about both....I've looked for customer service email addresses and nothing obvious pops up. The web sites should have a contact email front and centre...