htc m7 sense 6 update running 4.3 after an unroot failure.

[Heather Zimmerman-miller]

Hi! I'm a noob, and recently acquired a HTC m7 AT&T that was rooted with aopk. It was returned to stock for me, and I went to update to sense 6.0. It downloaded, reset the phone, and it's still running 4.3 sense 5.0. I've read other forums mentioning RUU. When I went to check for a software update, it said that none was available and it was up to date with the current software. Any ideas or help on how to fix this? Thanks.