There is only breach of contract. Either your contractor conformed to the contract or he did not. There are no grey areas. Whether a breach is sufficient for you to repudiate the contract is very doubtful, the contractor must be given every chance to put it right. Being churlish, awkward or downright dilatory is not a reason to terminate - the contractor can do more or less what he wants so long as he finishes on time, to the quality and cost if there have been no variations and be late without penalty if the contract does not specify liquidated damages. You are quite likely liable for the contractors loss of profit plus general damages if all that happened is that you took a dislike to them and chucked them off.