If I were you I would definately...."cancel the contract and employ a better more professional company".

One of the oddities of these Forums is when the original poster deletes their question and it is difficult to contextualise the answers that have been given.

Roofwork can be highly contentious in terms of precautions, particularly for short duration work, but because it also tends to be highly visible can generate tirades on forums such as LinkedIn.

Usually the almost universal demand is for a barrier at the edge or at least the use of fall arrest. But putting up some barrier at the edge of the roof of a four storey building may often put those erecting and dismantling it (along with people in the vicinity - e.g. members of the public on the pavement) at greater risk than the protection afforded to skilled trades who might only need to be on the roof for less than an hour. Similarly, particularly on older buildings there may be nowhere suitable to attach fall arrest.

So, particularly for the small jobs, each case needs to be considered on a case by case basis to determine what is reasonably practicable. This will often be heavily dependent on whether there is permanent means of access onto a roof and, if so, how safe it is.