LPT: Each level of CSA (customer service agents) has a cap and limitations on what they are allowed to help with, sometimes how often per shift or week, and what "special" offers they are allowed to let you know about.
I've been passed to Tier 2 a couple of times after just asking immediately, or after the Tier 1 CSA realises I'm not willing to accept their resolution or the offers they are approved to suggest, which sometimes they have to document offering before being allowed to pass you up a tier. That varies.
This is particularly beneficial if you are thinking about changing any service provider, like your cell phone or internet.
All of these places have retentions departments they will pass you to if nothing else works (and you are nice), so you can also straight up ask to be put through to retentions if you get bored turning down their only slightly cheaper packages and offers.
It's typically Tier 1, then Tier 2 and then retentions. Be polite and understanding at all times and you will get better service and a better resolution.
Can save a fair amount of money if you know this stuff btw....