How to restore WhatsApp chats with someone whose phone number was cancelled

[MJ53]

Hi, my husband passed a few months ago and I could see our WhatsApp chat until very recently, even though his phone number had been cancelled. About a week ago, the chat simply disappeared and I noticed that he apparently 'left' a group that we had with other friends. I really treasured the messages I had exchanged with him, and am v sad that I can no longer read them. Is there any way I can restore this chat? Some technical details:

(a) I have an iPhone 7; he had an iPhone 6
(b) I have tried to reinstall WhatsApp and then restore the history, but no success
(c) I back up my data on iCloud on a weekly basis

Any help would be really welcome. Thanks!

 

[Just_Me_D]

While awaiting a reply from those who use that particular service, head over to the service’s support site to see if they show a way to restore or retrieve the messages.