Shocking Service by Management

I have written to the Head Office of this establishment but alas, they have not rep****. On 2 consecutive occasions I have now been shockingly treated. I reserved a table and the last 2 visits, they have chosen to give the reserved table away. I was then **** to stating that they do not reserve table!! Why in the past have I had no problem? My wife was then told that the waiters had made a mistake - twice in a row! Not good enough and please don't lie to your clients!! I doubt that I will get a reply as even Head Office does not bother