Dazed and confused...maybe because I'm seventy....
.....but a few quid for a ten year old "feature phone" (see phone repair shop on your local high street) and a fiver for a Lebara SIM and a few minutes.....all cash.....and you're all set....completely anonymous....a few phone calls.....then repeat as above as often as you like.
My math says you can do this at least twenty times before you hit £350.
What am I missing here?
PS Just had a Sony Experia (Android) as an experiment with a "smartphone" for three months. HATED IT!!! Going back to recipe described above.