We had a retaining wall built when our house was pegged out but not built yet. We have now been notified by our neighbour that it is built 1 metre into their land, which once by checked by us, realise it has been. So we got the company who built it to fix it and they have now billed us for $1800, should we pay it? They had the plans plenty of time before and the house was all pegged out so had no reason to get it wrong. They did not discuss the price with us before the day they had to re do it and brought the variation the morning of when the machines and people were waiting, my husband felt pressured to sign it to get work under way. Do you think I can at least ask for a compromise on the price?