Experia M5 switching off when on LTE/WCDMA

<p>I have bought an Experia M5 cell phone. This phone does not work if it is on LTE/WCDMA, it only works when it is on GSM, what a useless phone. How can one buy such a phone only to use on GSM mode these days. If you need to use the internet the phones switches itself off; the bad part is that it will never switch on again unless connected to electricity no matter whether the battery is still full or not. This is a very bad product of Sony. A lot of people are complaining about it on the social media but sony is not doing anything about the problem, therefore Sony is not worried at all.</p>