How to Replace & fix a car fob for a renault clio 98?

Recently my central locking has been working when it likes!

I have noticed within the last week or so that the car fob works sometimes and stops when it likes, i dont think it is the batteries as they are new ones.

I have opened the back of the car fob and took the batteries out and put them back in but there are 2 metal things in side which hold the battery in place which are loose.

I have now noticed that the red light does not even come on! have i put it back wrong? can any one help?