Lindsay Lohan made an hysterical plea for help to her father,  as she claimed she was being kidnapped by Dina Lohan, screaming, "Dad, she's on  cocaine.  She's like touching her neck, and s**t" ... and TMZ has obtained audio of the conversation.

TMZ broke the story ... Lindsay and Dina got  into a ballistic argument after leaving a NYC club at 4 AM.  The two were  in a limo which was going to Dina's Long Island house.