When my lens is set to A it has a clicking sound and won't auto focus

Hi!

Given your input it appears that the AF motor of your lens is broken/ stuck. If you could provide us with the full product name of the lens we could point you to some repair instructions to fix them yourself.

Opening up a DSLR lens however is tedious work, you have to make sure no dust gets to the optics, no fingerprint smudges, lots of small parts etc. I'd take it to a local shop, see if they can fix it. Maybe they can let you trade the broken lens in for a certain amount off a new one...