I am intrigued by the use of the word "ethical" in this context.
In the original article I see mostly, and simply, poor customer service rather than a lack of moral principles.
Lying and cheating - which can including a company policy/philosophy of hiding underlying issues with untruths and obfuscation - is probably unethical. Poor systems and slow response to e-mails is just bad customer service and may rise from poor internal practices and even low staff morale rather than unethical behaviour.
Not being open with Delimiter, about why people were sacked, is not unethical for a private company - in fact, it could be regarded as ethical behaviour that respects the rights of those that were sacked. But how ISPs treat their staff (which may be at the heart of some poor customer service) - is another matter altogether
"Ethics, or moral philosophy, is the branch of
philosophy that involves systematizing, defending, and recommending
concepts of right and wrong conduct." - Wikipedia
Now you have to define "wrong conduct".