The truth is that this practice of "don't offer, but do if asked" is the basic operating method of most large companies. As a customer you have to learn to be equally careful in wording your requests. If someone calls in wanting a credit but doesn't say those words, there are many examples where you're not allowed to offer the credit. But if they're smart enough to ask for a credit, and they've never had one before for that specific issue, then generally you can provide it. This goes for banks, telcos, utilities, whatever.
The next time you're on the phone, if you get a response that sounds like the CSR has had to say it a thousand times, the truth is you're probably just not asking the right question.
Case in point: at two companies I've worked for, we've had a military discount. But, we weren't able to offer it, even if it came up in conversation. If someone told me "I'm being deployed so I need to make sure my wife can pay my bill while I'm gone," I would have been required to walk him through adding her as an authorized user on the account.
On the other hand, if he said the exact same thing and finished with "oh, by the way, do you have a military discount," then all of a sudden his monthly bill is going to get lower (lowered by a lot in one case.)