Navigon application bugs ?

[Aeglenzer]

Since updating to 1.3 update I have had several bugs like app. not saving recent address or home address not being saved when leave app. and later return to it! Some times voice instruction misses street names when it is time to make a turn ! Have tried everything that Navigon sugest to fix such as soft reset Complete restore to delete app. and put back from Itunes ! Navigon will never get back to me after sending them several emails ! It seems I am not the only one who has all these issues with this application! Is there any way to directly contact the App store so someone can address these problems or give me a refund ! Any kind other suggestion to fix! Gps signal is not a problem !
Thanks , Arnold