Currently bad batch in circulation?

I am a long-time user of the Porta Pro. Even if the design is worthy of discussion, the sound and the processing for the price it is not my opinion.
When I saw the version with telephone function for the first time, I was quite excited. The very open design combines the ability to make calls while driving wheel with a very good and cheap headphones.
My first model also fulfilled fully the benefits, unfortunately, held only half a year, but this was attributable to my rude handling.
So I ordered at the beginning of a new pair Jares. Since then I have about 5 return actions behind me because the functionality was disturbed either directly after unpacking or after a few weeks. While the headphones usually as usual their sound-mighty service do, you can not say that of the service function (three buttons on the left side of the listener) and especially the microphone. In particular, the microphone remains mute. This is certainly not on the phone, because the headset there included working properly.
It seems currently a very bad batch to be in circulation. That's a shame, because in principle I can only recommend these headphones.