Stuck in migration of data + cannot unlock screen

I download and install win 10 upgrade. After several resets phone is stucked at MIGRATING YOUR DATA (and keeps on reset itself after some time). Few times it shows normal screen but it cannot be unlocked....just shows Enter you PIN (with no keyboard anywhere around it). If i press Emergency call then keyboard will appear...but i cannot unlock it there.
My phone is Lumia 532

same problem here with Lumia 640xl. Help ASAP!