I work for a construction company and I'm new to lien waivers. So, one of our project manager needed warehouse space for one of his project and we got an space from a company. There was a lease agreement and 3months and security deposit needed to be paid upfront. I sent payment that was required with the lien waiver. Our lien are condition waiver and release on progress payment. Fast forward, our payment has clear the bank but we still haven't received the lien waiver sent back. The company that we sent payment got their legal team involve and said since there was already a lease agreement before the lien waiver and also the lien waiver was not part of the lease agreement. It was not required. How do I go about why we required the lien waiver and explaining it?