I have purchased a premium economy ticket but received an economy ticket. Premium was about 300€ more expensive than the same itinerary in economy. I have immediately (within three minutes after receiving the wrong ticket) contacted the customer service to inform them of the error. The very cynical and thoroughly unpleasant customer service agent Shabaaz Khan told me that I got the tickets that I paid for and that if I want to cancel my reservation I have to pay 60€. Which is what I had to pay because of their mistake. The agent then told me that if I am not happy I can send a complaint by email.