Garmin 830 + sensors

Hi all,

I purchased a Garmin 830 sensor bundle, but I'm having a few issues. 

Firstly, connecting my Garmin to my phone does not really work. Every time the connection is lost (due to turning off either device or bluetooth) the devices do not reconnect after switching them both on again. So every time I want to connect my phone to my Garmin I have to pair them all over again by deleting them completely first. Surely they should pair automatically when they are both switched on instead of spending at least 10 minutes reconfiguring them?

Secondly, I can not get the cadence sensor to connect to the Garmin. The other sensors (heart rate and speed sensor) work fine, but the cadence sensor does not do anything. I've taken the battery out, but that did not help. When I deleted the device from the Garmin and searched for it again it seemed to think it was a speed sensor when it did finally find something. So I connected it, but it still does not give a cadance reading. (when searching for the cadence sensor I was sure to spin the pedals, like you would when riding the bike). 

Is there anyone who can offer some help? Thank you all in advance.