Sound Error - BUG

Help me please!!! Here in Brazil, the technical assistance is very bad, they do not understand the problem and already want me to switch my iPhone ever made mistake to upgrade the ios.

I'm having a strange problem with the sound, I'll explain:

I used the ios 6 until recently afraid when actualize occurred errors that warned me. Updated one month ago my ios to 8.2 and began to occur errors.

The ringtone, alarm, voice recordings, play normally, but other sounds like the native music app, whatsapp videos and facebook, sound of the holy bible, play only with the headset.

I discovered that it is a bug and not hardware problem, because when I put the app "Relax M" for example, he does not play. I leave in the background and open a recording. Touching recording the sound of "Relax M" play along with the recorded sound.

These app that sound does not work on the external speaker of the iPhone, but they all work with the headset.

Another strange fact is that none of them can send the sound via Bluetooth to an external speaker, the error is replicated to the equipment, which despite paired correctly, does not touch the sound of those apps.

Already restored my iPhone as new, without backup, but the error persists.

Exist in log files countless "bug_type".

I am counting on your help!!!