Landlord & Tenant - Service Charges Legal - Admin costs dispute

Dear Expert,

I have received a demand for unreasonable Service Charges from the Managing Agent
My Leasehold studio is the smallest out of the 6 units and the Repairs/works carried out were not advised to me, additionally the type of repair and materials used is of a poor standard and requires remediation again

The Solicitors of the Managing Agent are demanding Legal Costs/Admin Charges and Service Charges which are excessively high.

I have not yet sent application to the FTT (First Tier Tribunal) as there is an application at the CNBC which is stayed(awaiting transfer apparently) to the FTT..

I have drafted a response to the Managing Agents Solicitors and would like this reviewed with the appropriate Legal areas mentioned

I would also like to know if I should proceed to the FTT or see if this can be resolved via without prejudice communications with the Solicitors of the Managing Agents

Please enquire if you have the appropriate Legal background

Thank you