I've found this under 'complaints' on the Barclaycard website:
Complaints
Our commitment to you
We're committed to providing you with the best service we can. But sometimes things can go wrong and we don't live up to our promises.
If this happens to you, we want to know. That way, we can put matters right for you and make sure it doesn't happen to another customer in the future.
How to make a complaint
You can contact us by email, telephone, fax, post or in person.
Email
Go to My Account and use the secure email complaint form in the Contact Us section
Telephone
Call us on 0844 811 9111 (call charges info)
Fax
Fax us at 01604 254 152
Post
Write to us at: Barclaycard, Customer Relations Department, 1234 Pavilion Drive, Northampton, NN4 7SG
What you need to provide
Remember to include all of the following information- it will help us to resolve your complaint more quickly:
Your name and address
The relevant Barclaycard account number
Any appropriate reference number
A description of your concern or complaint
Details of what you would like us to do to put things right
A daytime telephone number where we can contact you
What will happen next
We'll do our best to resolve your complaint quickly and with minimum fuss, but if we can't resolve matters straight away, we will:
Send you a written acknowledgement of your complaint within 5 working days
Details of who is handling your complaint and how to contact them. Sometimes this may not be the person who received your complaint but the individual best placed to deal with it
If your complaint is likely to take longer to investigate, we'll keep you informed of progress
We aim to resolve your complaint within four weeks. If we can't, we will send you a written update at that time to explain what is happening and let you know when we expect to complete our investigations.
After eight weeks we'll send you a final response or a further progress report on our investigations.
If you are still not happy:
We hope that we will have resolved the problem by this stage. However, if we haven't, or if you aren't happy with our final response, please contact the person or department that handled your complaint. They will work with you to decide the next course of action.
If this doesn't put things right, you can request a review from the Financial Ombudsman Service. This was set up by the Financial Services Authority to review unresolved complaints from personal customers or business customers with a turnover of under £1 million per annum.
We can confirm if you are eligible to refer your complaint to the Financial Ombudsman Service. Alternatively you can contact them directly at the address below.
Financial Ombudsman Service
South Quay Plaza, 183 Marsh Wall,
London E14 9SR
Telephone: 0845 080 1800
E-mail:
enquiries@financial-ombudsman.org.uk
Web site:
http://www.financial-ombudsman.org.uk