Communism is, by definition, "a classless, moneyless, stateless society".

When people say "no communist countries have existed" this is what they mean. Because that's not ever been achieved.

There are countries that are run by communist parties (China). But these are not countries that have "obtained Communism". You are confused because you never looked up the definition of a communist society.

For example, China is a country run by the Chinese Communist Party under a state structure of Socialism (with Chinese characteristics).

Since you don't understand basic definitions I doubt that you're criticisms of "communist countries" were very insightful.