Thank you for replies.
@Kate..The batteries are rechargeable ones and get replaced when the warning light comes on.As for thumping it,I wouldn't in case I broke a nail
That sounds ok then Eric,tbh the keyboard is excellent so I might look at a new mouse.As I have said the scrolling and cursor movement is fine its just the clicking,as an example...sometimes when you click on a smiley to use it will post 2 instead of 1.Then sometimes you click and nothing happens,as though you haven't clicked hard enough(I hope that makes sense)
I'm not sure how long they last for before they wear out..I have been using it most days for the last 3.5 years.