HELP!! Facebook crawler spamming my website

ok guys I need your help, looked everywhere and couldn't find any answers and I'm not a noob here I manage/create multiple websites and have a lot of experience managing servers. But this is something new..

I had an old website made in Magento, I erased everything and installed a Wordpress website. Now Facebook crawler keeps on trying to crawl old pages and mostly old images which do not exist anymore and this causes my server to use to much resources "it's getting ddosed" . I installed a plugin to redirect those pages to my homepage "301" I blocked Facebook ips "temporarily" nothing works. It crawls multiple times the same freaking images, logically I would thought that the crawler would realize that those images don't exist anymore and stop trying to crawl them, but this is not the case.

Need your help and advise

Thanks in advance

Alright, just in case in the future someone has the same problem as me. Apparently the old website had a Facebook page with hundreds of posts linking to the old website.. had to delete all of them, problem fixed!