my facebook account is hacked. how can i access my account back?

[Tracy]

so this is the story.. it was yesterday when i try to log in to facebook. but i can no longer open my account. so facebook sent me a security code on my mobile number so i can confirm my identity. but the problem is, they sent the code to my old mobile number (yes i have the simcard, but its damage.) i tried so many ways... i went to the outlet store of my mobile network and asked them if i could request a new simcard with the same number. but they said its applicable only for postpaid user.. (and i use prepaid simcard) simcard thing is fine. but my problem is i cant access my facebook and that account is so important. as in ! pls help? anyone?