Where can I buy the parts for repairing my broken headband?

i have this headphone for like couple months, and the part of the headband starting to break, i have glued it and have been trying to do so like the other answer but it wont get any better, it's only getting worse by the glue and the wire.

i decided to buy the part, and i wanted to ask if the sony are selling one of those, cause in my country they aren't.