I've been with italkbb.com for more than 2 years, but I believe their service was great regardless of the sound quality and sometimes got disconnected while talking on the phone. Compared the local phone bills with italkbb, I actually saved a whole bunch of money by joining it. Sorry, I don't think italkbb problems had bothered me ---> if I don't have a dial tone, then I'll use my cell phone instead. I like italkbb because it's provided all the features for free, esp. Caller ID (lets me know when I should and should not pick up the phone). In addition, I could call so many friends and relatives who live in Asia (China, Taiwan, Japan, Hong Kong, Malaysia, Singapore, New Zealand).
I'm currently using the Verizon Fios for the internet. Not sure is it because your high speed internet problem impact the italkbb quality or not.
Noted: my local phone company is Verizon.
I'm sorry to hear that you don't like italkbb. If those sales person truly bother you, try to hook up a caller ID so that you don't pick up those unwanted calls, esp. those 1-800 phone #s. In addition, you could lawsuits them after they kept on calling your phones for 3 +times (make a record and write down the time, place, person's name, company name, etc).