I have an Alcatel One Touch Idol 3. Occasionally, instead of ringing like it should (using the ringtone I selected as default) the phone just gongs slowly. It particularly happens when my son calls (I have no idea why). The problem is that the gonging sound is quite low in volume, and I almost always hear it too late to answer in time. Does anyone else have this problem, and if so, how can I fix it?