hi , we have installed tlc herringbone lvt onto softlay fleece over karndean which was laid onto ply. the lvt is indenting just under the legs of the sofa, customer wants all of his 3.5k back as he says the products are not suitable. all was installed correctly as per manufacturers instructions. have told him to use caster cups but hes adamant we have done this wrong. would be very interested what you all think. whats the law on indentation on floorcoverings and having to use caster cups? thanks for your replys in advance.