You may still be hurting yourself more than you hurt them. I say may since I don't know your circumstances, but I am missing out on communications from my employer since they insist upon using WhatsApp.
I agree since they should not be using WhatsApp for internal communications. The problem is that they do not see it that way since it adds additional hurdles with respect to communications from their perspective. That is especially true since I am the only holdout and few people seem to know how to use the organization's email system with any degree of proficiency.