If you notice any software malfunctions with your Vivo Y28L android device, you're most likely required to download and flash stock ROM firmware on your Y28L to permanently correct the software errors you noticed on your Vivo Y28L. And when you load stock firmware on your Vivo Y28L using any Qualcomm flash tool, your Vivo Y28L will be reset to factory defaults settings and by that, definately, your UserData will be lost including contacts, messages and others.
If your device has been bricked and want to unbrick it, you will need to pay closer attention to the tutorials contained below here.
Vivo Y28L Stock ROM Firmware Download Link(s)
1. Vivo Y28L_319865.KTU84P (Android 4.4.2)
How to Flash Stock Firmware On Vivo Y28L
1. Download your Vivo Y28L stock ROM firmware from the link above.
2. Extract the Vivo Y28L Firmware you downloaded from the link above onto a folder on your PC.
3. Download and install Qualcomm android device drivers on your PC. You may skip this step if you have installed Qualcomm drivers on your PC already otherwise, download Qualcomm drivers here
4. Now, choose either of the tools listed below here to load the stock firmware on your Vivo Y28L.
Note
1. Each of the tools listed above contained step by step guides with illustrated pictures on how to flash stock firmware on your Vivo Y28L.
2. If your device is bricked already, I recommend that you use Tool Studio eMMC Download Tool or QPST QFIL.
3. If you require any further assistance, simply drop your comment detailing the issue(s) and I shall help you revive your Vivo Y28L, if need be.