check for any firmware updates available first... if still not sorted then do the hard reset while with a good amount of battery power left... if it's still happening after the hard reset then let the retailer know especially if it's within 30 days (UK normally swap for new) after 30 days that is when normally it's a warranty repair.
ok I would definitely contact the retailer or manufacturer. sooner the better... a hard reset should have fixed that... I was actually guessing it would have sorted the issue. sometimes it's a worry that it's just a temporary fix. hope it all gets sorted.