Well, that isn't the best, but it is still better to have a choice than be stuck with only one ISP.
This works for both Comcast and FiOS, and I assume most other ISPs. They have intro-pricing for new customers, that expired usually starting 1 year(Comcast and FiOS), and sometimes gradually increasing over two years (FiOS). After the increase, you can attempt to renegotiate a new price, but rarely do they ever offer something as good as the price you were paying as a new customer.
So, you can become a new customer. This is easiest with having at least 2 available ISPs, and if there are not contracts. But, it is possible to become a "new customer" even with one ISP.
For you, the easiest thing to do is to go to the crappy CenturyLink ISP for a month(assuming that there isn't a contract), and then switch back to SuddenLink once you are considered a new customer again(assuming that it is a month for SuddenLink). Sign up as a new customer with SuddenLink, and benefit from the great intro pricing.
I have been doing this for a decade, and have switch ISPs over a dozen times.
I just recently switch back to FiOS (100Mbps down @ $39.99 a month) from Comcast (300Mbps down @ $29.99 a month) back in March. I tried to renegociate a new rate when my prices were about to increase, but the best Comcast deal I could get was $70 a month.
So, I switched.
I have many neighbors that are paying over $200 a month for the cable/ISP bills, but I have not paid over $60 in the past seven years, and I haven't paid over $40 in the past five years.