All human languages, even computer languages and animal communication have rules. It's called
grammar. Spelling also has rules, too, and as pronunciations that don't appear to follow any rules, such as the vowel sound in "put" and "but", it's because they are either a result of historical sound change, which has rules, too, or the words were borrowed from other languages.
If you want to argue that language does not have rules, you'll have to be more specific in how you phrase your statement.
