Bathroom shower screen stain

Hi Mark
I have bathroom stains as per photos, which I caused by spraying clove bud oil. Clearly I did not dilute enough and/or left it on the plastic for too long.
These stains have been present for more than three years and I have only really tried Gumpton Paste and weekly cleaning with “Earth” bathroom spray, as I did not want to make it worse.
Could you tell me what I could possibly use to either take away or even reduce the degree of staining. Hoping you have an answer for me.
I did try looking on your website for any answer to this sort of problem, but did not find anything that could help me.
With thanks for your time.
Debbie