Amplicom M6000 - little quirks and now broken

I bought this phone for the end of 2011 my mother (84, hard of hearing). Exactly 1 month after expiry of the warranty, it is now defective. I had already the feeling that the listener was quieter. Now the listener is only quiet and distorted sounds, there are only fragments to understand. I opened the phone and there are no contact problems exist (as expected). The small earpiece has not coped with the volume of 5 in the long term.

One drawback of the 90% of all hearing impaired people have mobile phones: The rocker for volume control of the ringtones and the earpiece volume is on the side exactly in the grip area of ​​the fingers. Old people hold the phone firmly usually spasmodic and so my mother constantly adjusts the ringer volume and the earpiece volume. We have become almost mad to explain that this can be adjusted only in one and the other only with no phone call. The hearing aid compatibility with M4 / T4 did not apply. There were ample noise audible. The operation ... well! No menu lock available and the menus are too complicated for the elderly.

Are you still fit and hear only bad is the device OK. Elderly and people with restricted - NO.
2.5 stars from me even if it is not so bad, I do not buy it again.