Under the Access to Neighbouring Land Act, you are allowed to have reasonable access for any work required to preserve your property. That would include cleaning windows would not include putting the sky dish up.
If they will not grant access for you to do any maintenance to windows, gutters, walls et cetera, you can apply to court for an injunction and legal costs, with the injunction specifying that they must allow you access in the bay don’t, they are in breach of the order and liable to be arrested.
Can I clarify anything for you?
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We can still exchange emails. Best wishes. FES.