Wow it's been a million years since I posted on these forums. I've been a member since pretty much the beginning, but mostly lurk.
Any way. I bought 3 yf-21's. The first 2 were both mint ( one from BBTS and one from Amazon). So I rolled the dice on a 3rd one from Amazon which had the bent antenna. I contacted blue fin re replacement antenna in late November. I emailed them every week looking for status. Finally in January they wrote back and said they couldn't guarantee they could send a new part and told me to return the toy to Amazon. So I held it until the end of my return window and then sent it back.
Got the new antenna via FedEx today. I guess I'll keep it in the bank. A pretty valuable piece of plastic. ✌🏼