First off, welcome back "Claymore" (Brian) it's great to see you posting here again.
2nd, like you, and as I hinted in a PM to you earlier, I too have had the misfortune to have some dealings with Bank Santander. Based on that experience I must say that you should NOT blame yourself in any way for your difficulties with them, because I have found them to be the most incompetent bunch of fools I've ever had the misfortune to come across - and that's saying something!
I'm sure that MikeG above (and hopefully others?) have their own good experiences with Santander, but without going into too much detail I was involved with them last year and it was - and remains - a horribly frustrating experience.
The circumstances "only" involved a death at 3rd hand so to speak, so I wasn't dealing with their "Deceased Dept" - at least not initially - but I found them to be utterly incapable of reacting in any sensible or logical/common sense way to the proven information I presented them with by E-mail, phone, and registered letter.
It seems that their "Help Line" and other "back office" people were equipped at birth with only the bare minimum of brain cells necessary to maintain basic life, and that in recognition of this the Santander "Company Ops Manual" (or whatever it is) allows nobody there any scope whatsoever for showing even a modicum of initiative or normal day-to-day common sense.
My own dealings with them continue to rumble on now for almost a year, to the extent that I now ignore them completely and all their letters go straight into the bin unopened. Thank GOODNESS that they have nil branches in Switzerland (though many of their staff don't seem to know that fact)!!!
I think it was early this year that I heard that Santander have been fined a substantial amount by the UK authorities for their multiple failings, especially when dealing with relatives of deceased account holders. I'm not at all surprised at that, and hope the fine was truly swinging!
So truly Brian, IMO you should NOT blame yourself in anyway for any difficulties you've had with Santander - to (mis)quote a well known old TV beer ad - "Santander. Probably the worst bank in the world!"
Cheers Brian, and welcome back mate