renault clio?

Hi i bought a t reg renault clio & at the time the mobilisor had been by passed, i was given one key that doesn't have the immobilisor button it's just a key. i had a p reg auto clio which seller took off me that had same prob & leaked. i was assured i wouldn't get wet & i have. The battery was changed with jump leads keeping the connection. 2 months on & for no reason i had been driving car but went out to start it & i could hear a ticking put key in & turned it, well it has an ear splitting alarm & immob had turned themselves on again.I have read what alot of people are saying but they have the proper key & wondered if this PEP would still work. If anyone can advise i will be so grateful thank you jane