I have just returned to Heathrow from BangkoK and can only say my flights were very disapppointing. Form LHR to Doha my Silver status did not mean anything, because my ticket was booked via an award ticket. Hence you are not given a food preference, a customer questionaire or even recognized has a frequent flyer. Doha to Bangkok I was in the middle of a long queue and on reaching check-in I was told my seat 17a had been given away and there were no more seats in economy. Although the second cabin of business was empty the supervisor decided he was not opening that section even though 3 Silver holders and 3 other passengers had also lost their seats. After a long stressful conversations with the ground crew and showing my onward flight ticket they decided to overrule their supervisor and let me into their business class cabin albeit on an economy basis. Once on board 6 other passengers were also moved from economy into business class cabin due to duplicate seat numbers. From the tone of the pilot voice he was not happy, we finally got away 90 minutes behind schedule. Although I did get into business class I still wrote to customer services about my ordeal. The reply I got is has follows- Qatar Airways, like most airlines, overbook certain flights where necessary. This has become a necessity in the airline industry as a result of the significant number of booked customers who fail to show up for their flights. It allows airlines to accommodate the greatest number of customers who want to fly and hence, allows airlines to maintain affordable fares. In such cases, our ground staff will make alternative arrangement to mitigate any inconvenience caused to the affected passengers. I disagreed with this statement, due to already being in the air for 6 hours, but still have not received a reply. On my return journey i was informed at Bangkok that my seat 17a had been given away 48 hours before the flight departure and I was now sharing 14c with another customer. I was given another seat at the back of the aircraft and once again not recognized has a Silver member due to my award ticket status. The strange thing is on looking at my Privilege Account it actually shows I flew home in First Class which has now confused the issue even further. Speaking to some frequent flyers they were all identifying the same problems and felt their voices were going unheard. Hence I also think Qatar needs to improve and look after its frequent flyers in the future to retain its 5 star status.