What is the ruling of Islamic law regarding a sponsor's refusal to grant a worker leave before the debts owed by customers, which the worker authorized them to incur, are settled?

This worker is a special employee whose hand is the hand of a trustee. He is not liable for perished funds except in cases of transgression or negligence. Therefore, he is not liable for future funds as long as he acted within the scope of what he was authorized to do. It is not permissible to link leave to debt repayment. The reference for leave is the contract between them, or the prevailing custom if they have not agreed.