Comcast cable Being ripped off by Comcast Internet

Comcast advertised Cable TV service at $29.99 for the first year, and from month 13 to 24, it will be $49.99 with 2 years' contract.  However, right after the first year, they charged me $68.49.  When I called them up, they mentioned the plan for $49.99 is no longer available.  I told them I'll file complaint with BBB and the California Dept. of Consumers' Affairs. 

I have all the "screen shots" with the advertisement from the computer and even the "chat log" with customer service at the time I signed up on the Internet, everything written in black and white.  I made a point to verify with customer service so everything is clear and written.  After quite some time, they talked to the manager and finally agreed to the new lower rate.  If i have not been watching my bill, I would not have realized that I had been ripped off.  They know how to lie, being dishonest and rip off customers.