TECHNICALLY ERROR WITH WHATSAPP RESTORE

Hi Apple Support . I need your support for restor my backup . I thought that its a technical problem but it was all for me my backup was everything for me . I lost my mobile The model was iPhone 12 pro max and when i install the whatsapp in 11 pro max there was a problem with restore messege . It was very annoying that how icloud made a backup of 5.39Gb because i never buy cloud plus storage you can see i also attach snap shots and i think that i was a technical error so i buy cloud plus storage but got nothing please help me to get my bakup back it may be your error or iCloud . I did not know . please tell me the possibilities how can i get my backup and resotre messeges i also change mobile phones and place same apple id on every device . I have no world for my tease .Please help me . I have access to my all contacts and the same apple id that i was use in my stolen mobile phone. The IOS VERSION was same on both devices .I need my whatsapp backup until 17oct,2021. I also araise the same question in Whatsapp Team Support.

Thanks Apple Support

HOW ITS POSSILE PLEASE TELL ME