Start at the beginning by complaining directly to the source of the problem.  

-- Go back to the shop

--Go to the Travel Agent

--Write to the service provider

Ensure that you talk/write to someone who is appropriate

Don’t be fobbed off with someone who cannot progress your complaint

Ask to see the relevant manager/complaints officer

Always try to get the name of the responsible person, and address them by name

Write to the Head Office

Ask name of Customer Service Manager

Consider contacting your credit card supplier if you used one. They may be jointly liable

Discover who the ruling body/trade association is

Ask if there is an arbitration scheme

Visit web/CAB/trading standards to find regulator/ ombudsman    Resources Checklist

As a last resort consider going to law

Go to Going to Law Checklist

Go to complaints procedure Checklist