“So rather than spend the money to upgrade their bandwidth, they cut the services?”
Uh, yeah, as does every ISP. Like any other business, they try to cut costs and maximize revenue.
IN fact, the last Comcast contract I saw said “best effort” or words to that effect. If you want guaranteed bandwidth, you need to get your own fiber uplink to a major backbone — call Level3, UUNet, etc etc.
Then they have no right to expect guaranteed amount of funds in payment each month. They'll have to be satisfied with "best effort", otherwise the contract is inequitable.