Connor King
Hi Anna, that is really quite upsetting to here that other tradesmen are this lazy. The only thing you can try is to breakdown the grout. It is comprised of Portland cement and notoriously difficult to breakdown. You can try brick acid or go to a tile shops and ask for grout remover / acid. PLEASE BE VERY VERY CARFUL AS THIS STUFF WILL HURT YOUR SKIN AND DAMAGE CLOTHES ETC. If in doubt ask a professional to assist. Hope this helps Connor