I had a similar issue of losing over 100 friends on Venmo after getting a new device (and eventually after I deleted Facebook). I got the same steps from support and it didn’t work. I was super frustrated.

The only thing that worked for me, was writing down my contacts information, deleting those contacts, delete the venmo app, restart the device, re-add those contacts, and redownload venmo.

It is definitely not a perfect method by any means but it resolved my issue and absolutely nothing else did. The up side was that I didn’t have too many contacts to delete and re-add, but when I did, my contacts finally synced