If you have complained to a bank, finance company or insurer and they have not upheld your complaint you will likely have the right to refer your complaint to the Financial Ombudsman Service (FOS). The address and contact details should be included in your final response letter.
The FOS is an alternative dispute resolution provider designed to decide complaints between consumers and financial service providers.
The decision is binding on the finance company, but not the customer, meaning you choose whether to accept the decision or not.