Keep it to the date, what happened and the remedy you want. The duty of reasonable care and skill in section 49 of the Consumer Rights Act 2015 binds any after-school club in business, and if the childcare missed it, section 54 entitles you to have it put right free or to pay less.
Rate a booked after-school club below four stars and you are asked whether to send it to them first; we follow it through. Then you review.
Registered childcare must have a complaints process, so use the after-school 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.
If the after-school club will not refund or put it right, a small claim needs no solicitor: up to £10,000 in England and Wales, £5,000 under simple procedure in Scotland, and £5,000 in Northern Ireland.