Owenski

On route home last night my right hand switch gear decided to move (rotate). Tried to tighten the screws up last night but I cant get them any tighter, its better than it was but it still rotates round the bar.

Any suggestions?

My thoughts currently lie between;
Should I be replacing it
or
Just taking it off an wrapping some inner tube around the bar for it to grip onto before putting it back on.

And has anyone had this or similar?