New member convertible problem

Hi I'm kirsty and I live in Kent and I have a Renault megane 2002 convertible ide 2.0 which currently won't start. I broke down just before Christmas drive belt slipped off due to oil leak I managed to drive it 5 mins down the road to get to a safe place to leave it until it could be recovered a week later, once I got it back I replaced the belt all fine no problems until I went to start it so it would not start so tried to jump think the battery was dead due to standing but no battery is fine. When I go to start it the lights on the dash come on like normal then when go to crank it over they dissappear and car makes a clicking sound. Any ideas would be great as need to get it running so it go in the garage to have oil leak sorted?? Thank you for reading