MAGIC JACK unuseable telephone service Internet, Florida

We purchased a MagicJack to replace our existing home telephone service.
When we got online, and set up the product for use, we purchased an extended warranty and a second year of service for 20.95.
When the MagicJack was up and running, we tried it out.  We could barely hear who we were talking to, and they could barely hear us.  At times we could not even get a dial tone. There was always lots of background noise.  We went to tech support to see if we had done everything right.  We had.  We then went to online chat.  For days we chatted for hours with tech support, who basically had us do the same things over and over. I would tell the person on chat, "I have already done this about 5 times, do you want me to do it again, it will not fix the problem".  Then they send you to a "higher level" of support with the same result.  They "assured us" that purchasing a new MJ would solve the problem (For 9.95 shipping and handling)  We had the exact same result with our second MJ.  We did everything Tech Support told us to do and nothing worked.  After over a month of using our fax and cell phones to make calls, we asked MJ to disconnect our service and refund our 20.95 for the extended warranty - to our amazement, they wouldn't refund the 20.95!  We contacted our credit card company to dispute it.  Our experience with MagicJack is that for us, it is unuseable, tech support is horrible, when a problem is not fixable, there are no refunds of any kind.  It also does not work if your computer is off, or reboots as it sometimes does during the night.