Mk1 mx5 1.6 alternator belt stretching

Hi all,

My belt and pulleys started rattling a while back so I tightened the belt. All sorted and then a couple of weeks later it started again. So I tightening and all was fine.

Now it has loosened again! And I’ve adjusted to the max!

Any ideas. I have noticed that the alt pulley is bent and may be wearing the belt down (there’s belt shavings everywhere).

Shall I replace pulley and belt and see what happens?