claim one day expense due to change of flights !!!!?

i have booked ticket from one flight booking website for delhi to bulgaria via paris

DELHI > PARIS > BULGARIA

i had booked my flights 1 month back. due to some schedule updating now my connecting flight from paris to bulgaria is clashing with my flight from delhi to paris ,,,,,

so i had to shift my connecting flight from PARIS TO BULAGARIA on next day. so now i m forced to have a stay in paris for a day !!! even though i booked my ticket on time.

now i want to claim my expanse for a day. on whom should i claim??????

the website from which i booked the tickets or the airline company !!!!!!

AIRLINE company is saying :- it fault of Website bcz they haven't confirmed our winter schedule before booking the ticket.

Web Site is saying :- we are looking for what we can do !!!