My son bought a BV6000S and after almost a month it finally arrived.
So far he is having a number of problems getting it to work properly. Here is the list:

After being charged fully, after 2 hours, not using it, the battery drained to 25%. It seems to drain very quickly even when not in use.
The screen is very sensitive and will often type multiple letters.
Google Play Store is not responsive.
You can't get it to do a factory reset.
You can't change the cellular network settings.
It took a few hours until it recognized the SD card.

And these are only the problems he discovered the first day using it.
Is the phone defective? Does he need to reflash the ROM? Update the ROM?

what is the firmware verison on your device now ?