Exquisite Home Realtor ( half paid rental)

I'm the property owner, Mihloti Nkuna assisted me to get a tenant for my property. The tenant moved in the property and I was not paid in full for the first month. I made enquiries to Mihloti as the agent and she confirmed that the tenant had already payed to her account but she refuse to pay the whole amount for the rental, she only paid half and claimed the other half is for admin fees. I was not made aware of those charges as the agreement did not had any fugures in it. She also failed to provide me with the lease agreement for this tenant She's so unprofessional and inconsiderate.