Restore WhatsApp Older Than 30 Days

Hi guys,

I read online that you can easily restore deleted chats if they are not older than seven days with the back-up file. I also read that you can restore even older chats by using a file manager and then using the respective back up file from that time. I was trying to get back a chat from over a month ago by exactly doing this. I used the file manager to check for older back ups but there were only three back ups from the last days, no older file. Does this mean the old files are gone or can I find them elsewhere or by means of another app? Any ideas, suggestions?

Thanks a lot in advance!
Marina