Hello my name is ***** ***** I will help you with this.
Under Section 13 of the Sale and Supply of Goods and Services Act 1982 they have a duty to act with all reasonable skill and care
If not they are in breach of contract and then yes - you could not pay him
If he contests this and his fees are less than £10,000 if he tries to take you to Court then it would be a small claim
But based on what you have said then yes, I think you have grounds because he has failed to act with all reasonable skill and care
Can I clarify anything for you about this today please?