Hi. That problem is very common with mobicel devices, it is not very difficult to solve it. Follow carefully the instructions given below, read through the instructions before you apply the instructions. To fix this problem you do not need any computer or a special tool, you just need another android phone that you are going to use as a wifi hotspot. I would recommend you to use an android phone or you can use a wifi router if you have one.
First of all you will need to root your phone, you will need to download the kingoroot apk here using another phone and move it to your mobicel trendy using a memory Card. Open wifi hotspot on your other phone connect the mobicel trendy via wifi. Now install the kingoroot apk and run it. Click the root button and waint for kingoroot to successfully root your mobicel trendy. Once your mobicel trend is rooted, you need to download an app called chamelophon from Google play store and run it. Next click the generate button followed by apply. After that, restart your phone. Done!
If there is anything you don't understand please comment below using the comment button below.