can i refuse to pay full amount?

[speedysloth77]

my tradesman gave a verbal quote for a big job. on starting, they realised a large part of it did not need doing (joist removal and disturbance of ceiling below) and was not done. Other parts have not been completed as agreed. (treating other joists in house - surface sprayed boards instead).
Agreed job was to be done in 2 weeks (in Jun). Not started till end of october with constant putting off and no shows).
I have raised issues via message and have either received no reply, or they simply havent turned up the following day. Man stated job would take 5-6 days. Is now at end of 3rd full week due to non attendance or turning up for an hour at a time. I have already paid half the original quote . can now i terminate the job and not pay the rest?

No. Before going down that path, you need to agree a final date with the tradesman by which the job will be completed and make it clear that, if they don't meet that deadline, you will ask someone else to do it. You also need to make it clear that, if the costs of getting someone else to do it exceed the amount you owe the tradesman, you will be claiming the difference from the tradesman.