How can I make a complaint in the most effective way?

theguardian.com:

T empting as it is to vent down the phone for instant results, always complain in writing. It allows you to keep a record and a timeline, to marshal the facts and moderate your emotions. Email is best. Don’t forget to put your full name, address and customer reference/booking/order number to enable the company to identify you on the system. Make clear in the email title that it’s a complaint. Some firms cunningly stall complainants by concealing their contact details. If so, go straight to the top. You can find CEO email addresses.

Be polite, concise and lucid. Businesses are likely to take more notice of formal, grammatical emails. They’ll assume the customer knows what they’re talking about. Explain the problem clearly, attach back-up documents if relevant and specify what outcome you are seeking and your deadline. Don’t ramble. Don’t insult. AND DON’T SHOUT WITH CAPITALS!

Give yourself a mini crash course in consumer law via Google so you can cite any relevant regulations that back up your claim. A good starting point is the Consumer Rights Act 2015, which requires traders to refund, repair or replace goods (or services) which are not as described or of satisfactory quality. Citizens Advice offers template letters, or you can connect via the complaints website Resolver.

If your initial overture falls on deaf ears, escalate it by following the company complaints process, which should be detailed on its website. At this stage, it’s worth keeping a log of whom you contacted when and what the response was.

If that fails, your next step is an ombudsman or alternative dispute resolution (ADR) service. Some sectors, such as finance, energy and telecoms, have to be signed up to a scheme, for others it’s voluntary. The company