Recently, a Time Warner Cable customer who had signed up for one of the company’s two-year offers was surprised to see their cable bill jump by $15 per month after just one year. After making multiple calls to Time Warner Cable to ask why their bill had increased from the rate they thought that they’d locked in for two years, they were told that TWC reserved the right to increase their rates after the first year of the promotion. Furthermore, they were told that it was “only” a $15 monthly increase, which is still below the rate they would have been charged without the promotion.

How can Time Warner Cable get away with this? Mostly because the company never offered the customer a two-year contract that would have locked them into a set rate for a given amount of time. Instead, the company gave them a two-year promotion that they agreed to over the phone.

The customer in question, who first wrote about this issue on Reddit, explains that the upside of such promotions is that there’s no obligation for them to stay with TWC. On the downside, they think that it’s not fair to offer a low rate as a “two-year promotion” when in fact the rate will go up after one year.

“There is no commitment, I was and still am free to go,” writes the customer. “It was just a new customer ‘promo’ price. There was no contractual obligation to stay with them. It’s just shady deceptive marketing. The fact that this is how it ‘usually’ is shows why most Americans hate the cable industry.”

Time Warner Cable tells us that it “offers promotions that provide new customers with prices that are below retail level” and that “our promotional materials and customer service agreements do explain that, over time, monthly charges reach full retail price.” The company also says that its representatives work to “help customers understand this pricing structure, and we apologize for any inconvenience experienced by this customer.”

Nonetheless, this really is a case of buyer beware. Thanks to the service agreement contracts that we sign on a regular basis, we’ve become accustomed to thinking that accepting a two-year offer of any kind will lock us into a certain rate. As this story shows, however, that’s not always the case. So if you’re signing up for one of TWC’s two-year offers, you should really make sure to ask them about potential rate increases so you don’t get a nasty surprise in your monthly bill after the first year.