I know you are trying to help but this should not be your concern. It is up to the executor or the son to deal with this as they will be acting on behalf of the estate, and at the very least it is up to them to contact BT and have them send out a bag, if required, to your address.
Problem now sorted, I rang BT again and went through to a different dept and spoke to someone sensible. They are going to send me the packaging and label so I can return it all.
Thank you for all your suggestions.
Make sure you keep the proof of posting slip.
No broadband, he didn't have a computer or tablet of any type or even a mobile phone. The equipment was in preparation for when landlines are being switched off for later this year.
Now that is something that I always do, even after it has been marked as received. I will hang onto it for about 6 months, just in case.