I'm ringing it from spark landline iphone6.

If phone is locked it comes up with slide to unlock, but no sound

If unlocked it comes up with accept or decline buttons.

Things I have done to try and resolve,

Powered phone off and on.
Set ringer to maximum volume, hear sound fine when altering volume
Checked do not distrub is off, manual and sceduled both sliders are in off position, and there is no moon icon on screen.

Ring tone is by the seaside, I've changed to different ring tones and had no success either.

In notifications, under phone allow notiifcations is green, and notification sound is by the sea side.

Anything I missed, otherwise I'll take it into a 2degrees shop see if they can help. Thanks

Edit, i got the vibration to work, taken off title.