Explain, in writing, what was wrong and what you would accept. If the childcare was not delivered with the reasonable care and skill that section 49 of the Consumer Rights Act 2015 demands of a breakfast club in business, section 54 gives you a repeat at no cost or money off.
When a booked breakfast club gets under four stars, you choose whether they see the problem first, and we follow it up with them. Then you review.
Registered childcare must have a complaints process, so use the breakfast club's first. If that does not settle it in England, complain to Ofsted about a registered childminder (or to the agency, if they registered through one); in Scotland the Care Inspectorate takes complaints about registered services; in Wales and Northern Ireland, contact CIW or the Trust that registered them. If a child is at risk, call the council or 101, and 999 in an emergency.
A claim against a breakfast club for money back can go to court without a solicitor — £10,000 is the limit in England and Wales, £5,000 in Scotland (simple procedure) and £5,000 in Northern Ireland.