usb port does not support data transfer

Outside of the obvious fixes that I hope you've already done, the next logical step would be to replace the charging port. Being subject to mechanical stress from being plugged and unplugged generally once or more a day, they are prone to getting broken.

The things you should try first would include:

• Restart the phone
• Try a different cable
• Try a different USB port
• Try a different computer
• Clean the port with compressed air/isopropyl (at least 90%) alcohol/eyeglass cloth/toothpick (nonmetallic only)

As a last resort you could try restoring the phone to factory settings, but only if you have a current backup since you'll lose all your data if you do so.

Anyway, as far as cell phone repairs go, replacing the charging port on your phone is fairly easy. It's mounted on a separate daughter card so that card can be replaced without soldering. A quick glance online shows that it's available very inexpensively. I wasn't able to locate a written, iFixit-style guide for you, but there is one available for the Y20S. As far as I can tell, the only difference between the two is the Y20S is available with more memory than the Y20.

Manuals / Vivo Y20s / Auxiliary board - Nobody Calls Me Chicken

I watched through a video specifically made for the Y20, and could not find any difference in the procedure from the Y20S guide. However, if you want to check for yourself, or you prefer watching a video, here it is.

Vivo Y20 USB Charging Port Replacement - YouTube

As you work, take lots of pictures and once you're done you can use them to create your own iFixit guide to replacing the charging port. It's easy, fun and will have the appreciation of the repair community and those who come after you with the same problem.

Create a new Guide - iFixit

Good luck with your repair, and be sure to come back and let us know how it went; your experience could help someone else.