I’d send it back. It's a faulty product, return shipping should be taken care of by the seller so it shouldn't be difficult at all.
Regarding fixing it yourself. You can try matchsticks/wood shavings and glue, but it my experience (particularly with strap buttons), it's rarely a permanent fix. You would likely need to drill the damaged thread out and fill with dowel and start again.
Regarding fixing it yourself. You can try matchsticks/wood shavings and glue, but it my experience (particularly with strap buttons), it's rarely a permanent fix. You would likely need to drill the damaged thread out and fill with dowel and start again.