Do you mean when the handset is switched on?
Check your volume settings in case the phone is set to silent, or you have a call divert in place etc.
If your phone is switched on you may miss a call if:
- you temporarily lost network signal
- you were on a nother call
- you didn't hear it ring
he is talking about call catcher or missed call notification (same thing) most mobile providers voicemail service sends you a text if some one gets to your voicemail but does not leave a message (it's very useful if you got intermittent coverage or phone is off)
it's a very basic feature that should be on giffgaff
you can use hullomail as its like iPhone visual voicemail, but do note every call that hits the voicemail takes one minute of talk time (more if the message is longer then)
I recommend that you set busy and ignore to default voicemail number (as your going to get the default missed call on the phone) and set the no responce to hullomail
assuming your using android, goto your call forwarding page on your phone and copy the number down (should be +44,,7802,,091,,904 [remove the dashes] and then install hullomail and make an account once it's installed and setup go back to call forwarding and put the number back I to the busy and unanswered/ignore ( +44,,7802,,091,,904 [remove the dashes] ) but leave unreachable/no response as the hullomail number , so when phone is off or out of coverage you get a missed call notification from the hullomail app when your WiFi or data comes back on
but as I stated it costs 1 minute for every call that hits hullomail voicemail (as to why recommend using busy and ignore as Giffgaff voicemail)
Please mark the correct answer so users can find them later on