You can get the original promo price if you threaten to cancel. There's a song and dance with CSR but once they transfer you to the retentions dept, they are authorized to give you the original price again for a year. Actually, Comcast did give me a different deal once where the price was slightly higher than my original introductory offer but speeds were also better.
That trick had worked for me about 10 years ago. The last time I was buying my own plan, Verizon was not interested in playing that game. The 'TV bundle' was the only thing they would offer, which is why I ended up at $70 anyway. And that was in a city with another Cable internet provider and a (very slow) DSL option.
Most consumers don't even have another option, and the cable companies know you aren't going to just get rid of internet to spite them.
