Q: 5s goes to voicemail while locked. How do I stop this happening.

The only way that should occur is if you have Do Not Disturb turned on. http://help.apple.com/iphone/7/#/iph3dd60e1f

Make sure Do Not Disturb is not enabled.

-> http://support.apple.com/kb/HT5463

Jay70_uk wrote:

 

...  at the bottom of the screen it has a tick on while phone is locked and I can't get rid of the tick.

What's a "tick"?

The tick (we call it a check mark in the US) is only in effect when Do Not Disturb is turned on.

If DND is OFF, the selection of Always or Only while iPhone is locked it irrelevant.

Try a reset: Simultaneously hold down the Home and On buttons until the device shuts down. Ignore the off slider if it appears. Once shut down is complete, if it doesn't restart on it own, turn the device back on using the On button. In some cases it also helps to double click the Home button and close all apps BEFORE doing the reset.

You're welcome