The Unforseen Trauma and Further Loss Caused by Activatiobn Lock When an Owner Passes

It's not clear to me if you actually applied to Apple to have the lock removed, as in https://al-support.apple.com/#/additional-support. Even if you did, the proper legal channel for a deceased individual is outlined in How to request access to a deceased family member’s Apple Account - Apple Support

Note that those receipts have to be for the purchase of the equipment and must be from Apple itself or an Apple authorized dealership. Those are probably the only kind where Apple can verify authenticity. If Apple accepted just anything then they would be inundated with fake receipts. Keep your receipt after you buy an Apple device - Apple Support

You keep on saying "you". This is a customer to customer mutual support site (see the fine print at the bottom of the page). I am not Apple; I am just sitting at home having a coffee before going downstairs to wash the dishes. I have simply been helping other people on this site for 20+ years so I have some understanding as to how Apple does things. I know you are frustrated by all this and I am just trying to help you understand what you need to do if you wish to have access to this device.

A death certificate is not a receipt. The second link I provided is what the estate of the deceased person needs to do to get access to the account and to the device of a deceased person. If you are that estate then get your lawyer to get a court order as outlined in the support article.

The alternative is if you have a receipt that meets Apple requirements then you can apply for the device to be unlocked. There are many stolen devices out there that have an activation lock and if Apple were to just accept any piece of paper pretending to be a receipt it would defeat the whole purpose of people locking a stolen device.

If you cannot get the device unlocked then recycle it. From the very bottom of Apple Trade In - Apple :

"Does Apple offer recycling?

Yes. Apple Trade In lets you recycle any Apple device (including devices from Apple-owned brands) at any Apple Store and on Apple for free. That includes your batteries and old electronic products as well as free, on-demand packaging recycling for our commercial, education, and institutional customers. When we receive your device, it will be thoroughly inspected to determine if components can be recycled or reused. Whether recycled or reused, all activities relating to the processing of your device will be managed in an environmentally responsible way."