Cavity wall insulation

Access

I was horrified when one of our tenants informed us they had had cavity wall insulation done; the firm that has done the job carried it out without contacting us for our permission even though the tenants ticked the box for tenanted property. I am totally against cavity wall insulation in older properties. We have contacted the firm concerned and they have admitted they are totally in the wrong and have told us they will take it out ore compensate us with £120.00 as this is what it would cost to take it out (I think that is going to cost a lot more than that as they will have to replace all the bricks they have drilled) Any thoughts please.