How can I delete a presentation when I forgot my password and my email address doesn't exist anymore ?

Good afternoon,

My name is Sandy MEUROT and I would like to delete 2 presentations I made on April 15, 2014. The problem is that I thought Imy account was created with an email address that doesn't exist anymore (old university) sandy.meurot@etu.univ-lyon3.fr and I cannot remember my password... But the thing is that even when I try to reset my password, they say that the email is unknown. I tried with all the other emails I have, but it did not work.

Here are the 2 presentation links : 
http://prezi.com/gbvr5azch-u6/le-levier-interne-de-leconomie-residentielle/
http://prezi.com/v4bi9zesefin/mobilite-et-tic-territoires-bcp-permeables-systemes-ouv/

Could you please help me finding a solution ? 

Thank you very much.
Regards