AT&T provides DSL and/or cable broadband in various markets, but they have competition from other cable providers and private DSL providers. There is no monopoly. As a matter of fact, broadband Internet is an extremely competetive market. This part of your argument is incorrect, so the rest of it falls apart and need not be addressed.
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-264744A1.pdf
which indicates that something like 98% of American broadband is either over cable (throttleable at will by the cable owner to discourage competition) or telco (throttleable at will by the telco to discourage competition).
I'm PAYING for my bandwidth, it's not a gift from the pipeline owner to me, to Google, to Vonage or anyone else. I'm entitled to use that bandwidth for any legal purpose, particularly if I'm using it for a service (VOIP) which competes with other business lines of the pipeline owner.