Complaint letters
Put the problem and requested outcome in writing
Build a factual complaint that separates what happened from what you want the organisation to do next.
What to include
Account reference, relevant dates, a short factual description and the specific outcome you are requesting.
Keep evidence
Save invoices, emails, screenshots and a copy of the letter alongside proof that it was sent.
Check the recipient
Use the organisation's published postal or digital contact route for formal correspondence.