Consider obtaining a full breakdown and documents in support from the managing agent. You have rights to apply to the leasehold valuation Tribunal to assess the reasonableness of the charges. Consider also whether all tenants are in a position to buy the freehold and manage the block themselves.
It is advisable to mediate if given the opportunity. Mediation is not a sign of weakness. Often litigation cases can be resolved by discussion and sometimes parties are closer to settlement than they realise. Always take the option of mediation as it could save considerable costs. It is also very useful to explore the strengths and weaknesses of each side and mediation is a very good opportunity for this. Knowing the weakness in your case as well as the strength enables you to reach a favourable settlement.
This is often a problem that arises in conveyancing and there are no easy answers. Options include negotiating the completion with a sitting tenant, or agreeing a retention for any possession proceedings that maybe required. Always look at the tenancy agreement to see how best vacant possession can be obtained and the quickest way.
It is essential that you look at your disciplinary rules and grievance procedures before undertaking any disciplinary action. Look at the contract of employment to ensure that there is a definition of gross misconduct so that you know what conduct falls within that definition. It is essential that you record relevant matters and pay particular attention to the contents of your letter of dismissal.