I haven't been warned off for anything, you haven't provided proof off anything you spout, but still waiting, oh, and I haven't been claiming a pension for 15 years, more porkies.....
As for the OP, the pension claim form took me ages to fill in because they asked every employer since I started work, but that may have changed now, so I would forget the phone call thingy to fill in the form.
You have to 'claim' a state pension because it is classed as a 'benefit', I know daft...😏
The same as when you get your pension you must tell them if you go into hospital, prison or go out of the country, in case it affects your payment in any way....😌
Like many of us, if you move to a country not on their 'reciprocal agreement' list, your pension will be locked from that date. Of course there are those who use some sort of route to get a full pension, but that would be benefit fraud, so up to you....😉