That still doesn't explain why this seems to be tolerated with "free refills" but not with "unlimited bandwidth". And even if you were right, even if it's just

That still doesn't explain why this seems to be tolerated with "free refills" but not with "unlimited bandwidth". And even if you were right, even if it's just a case of false advertising and the provider wanting to get out, there is nothing wrong (neither morally nor legally) for them to unilaterally terminate the contract, which they could have well done instead of writing that notification letter. They explicitly state this in their TOS. Most companies can still (luckily) decide which customers they serve and which they don't