Update: They called two more times (looks like they were calling at 30 minute intervals). I answered the second of those calls, and promptly asked to be put on their do-not-call list. The guy on the other end apologized and thanked me for taking the call. They haven't called since. I've got my fingers crossed...
For the last two weeks, I have been getting calls from this number at least once an hour at all times of the day and night. I have called them over 20 times to have my number put on their "do not call" list, without any success. In fact, when you call, the recording says to press 1 to speak to a customer service agent, and 2 to have your number removed. Whenever you try to speak to contact customer service, the recording tells you that due to the high number of calls, they can't be reached. When they called this morning at 8:00, I decided to answer. A man on the other end started trying to sell me something, and I yelled at him to take me off his do-not-call list. Who knows if I'll have any luck.