Free video calls and voice seems ok quality. Problem is with Viber out. Due to some glitch I lost so much of calling credits I purchased. When I contacted the customer service they told me they cannot refund or compensate for poor call quality because I've use the calling credit. How do I know about the problem if I don't place a call? There are so many less than 30 sec calls in my Viber out call history which doesn't seems to be a proof of poor call quality for the customer service agents!