Conversion work looks at a specific hesitation. People leave before they understand the service. They understand it and do not trust the next step. They submit and never hear back. Each one has a different fix.
Change one thing you can explain: the heading, the form, the proof you actually have, or the page a campaign lands on. Then see whether enquiries change. A redesign of everything at once teaches you nothing.
Keep a note of what you changed and why, so the next month does not undo it by accident.