Or your could challenge the reasonableness of any service charges in the First Tier Tribunal, which is a no-costs jurisdiction unless you've acted unreasonably or unless there's a contractual entitlement on the part of the lessor to recover costs under the terms of your lease. But if the work needs doing and the costs are reasonable, there's little scope for winning on that front.
Or your could challenge the reasonableness of any service charges in the First Tier Tribunal, which is a no-costs jurisdiction unless you've acted unreasonably or unless there's a contractual entitlement on the part of the lessor to recover costs under the terms of your lease. But if the work needs doing and the costs are reasonable, there's little scope for winning on that front.