Same here. See below. I purchased my last key on 2/2/17 so that shouldn't have expired yet, and I CAN play pokemon on my phone so I have not been banned. Seems clear it's a bot issue.
INFO <b><font color="#0094FF">[18:36:21]</font></b> Started
INFO <b><font color="#0094FF">[18:36:22]</font></b> Next pause at pokestop is in 57 minutes...
DEBUG <b><font color="#0094FF">[18:36:24]</font></b> Logout Request: [PULSE][Invalid Session]
DEBUG <b><font color="#0094FF">[18:36:24]</font></b> NO HB: [PULSE][Invalid Session]
INFO <b><font color="#0094FF">[18:36:24]</font></b> Stopped
INFO <b><font color="#0094FF">[18:36:25]</font></b> Stopped