Welcome to the Bunnings Workshop community. Thank you so much for joining us and sharing your question about removing your shower handle.
I'm sorry to hear you are having trouble removing your shower handle. Would it be possible for you to post a photo of the current setup? This will allow our members to have a good look at the assembly and give you an informed recommendation.
Calcium and limestone deposits often occur on shower handles and spindles. This creates a stone-like bond between the two surfaces and makes it very difficult to remove the handle. You could try soaking the handle in CLR 1L Calcium Lime Rust Remover to see if it softens the deposits allowing you to pull the handle away.
Please keep us updated, we look forward to seeing the photos.