Where do we stand legally?

[Kurdswife]

Hoping someone can help us. We recently ordered paid for and built a made to measure garden log cabin. Upon completing the build we established that the dimensions of one of the internal walls was incorrect and wasn’t what was agreed on the building plans. We had planned to use the small room within the cabin as a bathroom but because the door gap has been manufactured wrong we are no longer able to do this. We contacted the manufacturer who said that the plans are what we agreed, and yes the plans are correct but what they have sent us do not match the plan...basically they are saying tough....do we have any recourse to this