Incomplete job

Builders installed laminated flooring but then the finishing could not be done at the inside doors to the bathroom and room. As per the t&c builders are responsible to sort this out when it is internal doors. The internal doors are hollow so cannot just be sawed off at the bottom. This is what the floor installers wanted to do with no regard for causing damage or anything. Now builders are telling me I must pay for a Carpenter to sort it out. This should be sorted out by you guys.