The lack of Wifi calling is debilitating. So many people (helpfully) offer advise that in the meantime whilst giffgaff think about Wifi calling, you can use a third party App. However, for someone like me who has no mobile signal at home (rural area) it severely limits connectivity to the world. Banks and services such as gas, electrictiy, water companies do not use third party apps when calling you. Tradespeople only ever call your mobile, even though you insist that your normal phone is the primary means. We have third party apps to call friends and family, but it gets very expensive having to utilise the normal house phone as well when I see month after month I am wasting my minutes with my giffgaff plan.
For anyone like me who really needs Wifi calling as an essential means of communication, then look at ID Mobile. They do monthly SIM only plans and offer Wifi calling with a bonus of having data rollover as well. So sorry giffgaff, I've been with you for a number of years, but it's time to move on.