Why is Truphone the only option?

I ask Apple this question - how do you persist with Truphone being your only carrier in Australia for family sharing on an Apple Watch?

I bought my 2 daughters a watch each at Xmas...the accounts are with Truphone, as that is our only option. One has worked from day 1 fine, the other has never worked. Says we have mobile account, but no signal.

I have been sending emails and calling now for near on 4 months to get it sorted.

1) they haven't been able to sort it out

2) they never reply to my emails, i have to ring every time to get any update

3) They say they will keep me updated, but never do

4) every time they say 'it is with the highest level of technicians looking into it'

I am at a loss as what to do.. wanted to let Apple know that they have an unhappy customer, and to get some competition in this space for consumers..

The family pairing option is perfect for parents who don't want kids on social media and yet still want to be able to call kids on a cool phone/watch..