Complain to a tradesperson about poor work

Help me complain to a tradesperson about poor work.

What was agreed: [quote or verbal]
What is wrong: [snags, with dates]
Photos: [yes/no]
Money paid so far: [rough]
What I want: [fix, complete, partial refund]

Ask me up to 3 short questions first if anything important is missing. Wait for my answers.

Then:
1. A firm, factual message with a reply-by date.
2. A snag list format.
3. What to do if they ignore me, marked to check on Citizens Advice.
4. What not to say.

Only use what I've told you, leave blanks for anything I haven't given, and don't invent facts, diagnoses or legal outcomes. This is help with wording and planning, not legal, medical or counselling advice; point me to GOV.UK, Citizens Advice, NSPCC (0808 800 5000), Childline (0800 1111), Samaritans (116 123) or Refuge/National Domestic Abuse Helpline (0808 2000 247) where that fits, and call 999 if anyone is in immediate danger. UK English.

Stay in this ChatGPT chat. Do not turn on apps or connectors, and do not use memory from another chat.