Hello and welcome to the forum
I'm afraid you cant just buy another keycard and reader from ebay
and expect that to work in your car. Its not that easy mate as the keycards are programmed to your cars ECU
whereas the readers arent programmed (so can be swapped between vehicles).
Your going to have to either go to a Renault main dealer with the correct documentation and order a new card (which comes from France and takes about 10 days) or try and buy a brand new (not already programmed) keycard from somewhere and then find someone (like a decent auto locksmith) to program it to your car.
You cannot re-program keycards once they have been programmed so save your money.