My husband, who ironically worked for BT, died nearly 5 years ago. At the time he was the "account holder". I spoke to BT at the time, took everything over, have paid all the bills since and MyBT has all my details. And yet, I still get told he is the account holder. I get mail offers addressed to him, I had someone call him wanting to sell him something last week and this week, when I had problems with email and had to speak to BT they told me - at first - they couldn't speak to me because the account holder information they had was different.
It doesn't upset me any more, but it really really annoys me. Every time this happens I tell the person concerned that the person they have down as the account holder has died - that I am the account holder.
I have notified the moderators of the forum about your problem. Once they have read this they may be able to help. They are a BT UK based team and if they can help they will reply via this thread asking you to contact them via a link. They are very busy at present so once you have replied to them by the link, it can take 48 hours for them to re-contact you.
I'm so sorry you've had calls asking to speak with your late husband. I can appreciate how upsetting this must be for you. I'm sure I can sort this out for you. Can you please drop me over an email with the account details? You'll get the contact the moderators link in my profile.