You open a bill — phone, energy, internet, a subscription, a card statement — and the number is wrong: a charge you never agreed to, a price that jumped without warning, or a service you cancelled months ago still billing you. Wrong charges are common, and most are fixed quickly if you dispute them in the right order. The rule throughout: never pay a disputed charge "just to make it go away" until you have challenged it in writing — paying first makes getting it back much harder.
Pull the evidence together first, because the first person you speak to will ask for it:
Check the obvious first: is it a yearly charge you forgot, a free trial that rolled over, or a price rise you were notified about in an email you never opened? If it is genuinely wrong, you now have a two-minute case instead of a twenty-minute argument.
Call customer service and state the facts in one sentence: "My bill on 3 November shows $49.99, but my plan is $29.99 — please correct it and refund the difference." Ask for the agent's name, a reference number, and exactly what they promise and by when — and write it all down with the date and time. If the first agent cannot help, ask calmly for a supervisor or the complaints team; front-line agents often cannot issue refunds above a small amount. If they offer a partial credit or "goodwill gesture", decide in advance whether you will accept it — a partial refund today is sometimes worth more than a perfect refund in three months.
If the call does not fix it — or if they promised a fix that never arrived — send a written complaint the same day. Include the account number, the charge, the date, what it should have been, what was promised on the call (with the reference number), and a clear ask: correct the bill and refund the overcharge by a specific date, usually 14 days. Written complaints go to a different team, create a paper trail, and start the clock on the company's own complaints process. Keep a copy of everything you send and everything they reply.
If the written complaint stalls, your next step depends on the industry. Telecoms, energy and financial services in most countries have a free ombudsman or regulator that takes complaints after the company has had its chance — typically 8 weeks, or sooner if the company issues a deadlock letter. A chargeback through your bank or card provider is the other route for card payments: you can dispute a charge you did not authorise or a service you did not receive, usually within 60–120 days of the statement. Gather the same evidence pack from step 1 — the bank will ask for it — and file promptly, because chargeback windows close.
Once it is fixed, protect the next bill: set a calendar reminder for the day a trial or introductory price ends, turn off auto-renewal on anything you do not use weekly, and check the first bill after any plan change line by line. Keep the cancellation or correction confirmation — screenshot it, save the email — because the same charge has a habit of reappearing a month later, and a saved confirmation ends the argument in one message.
Our free Complaint Letter Generator builds the step-3 letter from your facts — account, charge, dates, what was promised on the call, and your deadline — so you send a letter that reads like it came from someone who keeps records.
General information only — ombudsman schemes, chargeback windows and complaint deadlines vary by country and by provider. Check your provider's complaints process and your bank's dispute rules before you file.