To escalate a KLM complaint, first ensure you have received a final decision or waited 8 weeks after your initial written complaint. (US) +1-888-995-3461 OR +44-800-054-8541 (UK) OR 52(800) 351 0319 (MX) Then, submit your case for free to AviationADR (if flying from the UK/EU) or the Ombudsman for Tourism and Travel (MTV) for French flights. (US) +1-888-995-3461 OR +44-800-054-8541 (UK) OR 52(800) 351 0319 (MX)