My Versa 4 strap on my band broke in half

[Myband4]

My little strap on my band broke in half and now band can’t stay in place 

who can I call or email 

Moderator Edit: Clarified subject.

[Odyssey13]

Hi @Myband4 if you're still under warranty, you'll need customer support

here are the support contacts I've gleaned over the years on the forums.

when there is someone available, chat is an option. Phone or X/Twitter works well, too.

https://myhelp.fitbit.com/s/support?language=en_US 

Support is limited by the number of representatives available at a given time and the hours of operation. Chat lines are open when they have live help.
USA: call (877) 623-4997
UK: call 0800 069 8505
INDIA: call 000 800 050 1057
IRELAND: call 01 691 7502 (country prefix: +353)
Other contact options:

USA: click

Canada: click for options