I want to complain to facebook about something, is there a phone number or email I can use to contact them?

I wanted to change my name from Heather Marie to Heather Ann Mare, Ann being my grandmother whom passed away. I wanted to change my middle name to this in honor of her. But facebook will not accept my request. I mean, it's not like it's offensive or obscene. It's been a while since my request. I tried sending more, but still nothing. Is there anyone I can contact about this problem via phone or email? Please help. Thank you.