Sky erected dish and clipped cable onto my property

I live in a house which i own in a block development which has a number of flats etc.On returning home one day i have noticed SKY has errected a dish on the development roof and clipped cable accross the front of my house wall without my permission,for connection for sky users in the other flats etc.Surely they are not allowed to do this without my permission.Any advice would be grateful.

if its a leasehold property, (which it probably is as it is multi-unit) then you dont own the walls - the management company do. The dish installer should have got permission from the management company.