iPhone 5 carrier update issue

Hi, I'm using iPhone 5 and I'm facing an issue after updating my carrier settings 1 month ago, so I did without really knowing what this update meant.The update change my toggle to enable/disable 3G, it changed into LTE. My carrier is Emtel (Mauritius).

Since I always use EDGE because 3G drains my battery too much, I never enable it. After the update, when I disable LTE, it automatically switches to 3G, which is equally battery absorbing. So, I restored my iPhone 5 to a backup before the update so I would get my EDGE data network back but the new settings are still there.

Also, the internet tethering / Personal hotspot is no more available / appearing in my iPhone 5 (settings) used on iOS 7, 7.1, 7.1.1.

Grateful if someone / apple can give a rapid solution on this due to the fact that this issue is being faced by lots (thousands) of people I know who are using iPhone 5 on Emtel, which is a mobile operator in Mauritius giving LTE service on iPhone. Hope that apple will give a solution on this. Note my actual carrier on my iPhone 5 is Emtel 16.x.x used on iOS 7, 7.1, 7.1.1. Note that this issue is present only on iPhone 5 and other iPhone (4S, 5S & 5C) are not facing this issue. Looking forward ho hear from you. Note: already reported the bug, no answer since a month. All explained above occurred after the OTA carrier update.