Disgruntled (Ex-) Customer or: #palmersbetrug

As all my friends will attest to, I am as willing a marketing prey as they come. So when I spotted a big poster in the Palmers branch close to the office, announcing that because of their 100st anniversary they are offering everybody who spends EUR 100 or more a free flight to a European city (info in German here), I got excited, posted it on G+ and Instagram and of course rushed there to stock up on lingerie. I am not the biggest fan of their stuff to be honest as I find them a bit on the old-fashioned and overpriced side, but o.k.  I sent off the original receipt as instructed and selected my two dates (one in December, one in March) and destinations, Kopenhagen and Madrid. According to the small print, they, or rather the travel agency in charge, should offer me a flight to one of the destinations on one of the selected dates. About 2 weeks after I had submitted everything by registered mail, I get an e-mail from said agency (with a .co.uk e-mail address) informing me that unfortunately there were no available flights for these destinations on my dates of choice, but they could offer me a flight to Madrid on January 9 and I should reply within 72 THAT (not IF) I accept this offer. This date did not work for me so I wrote back, explaining that I was on a business trip at that time and could they please find me something to either Madrid, or alternatively, Lisbon in February or March. A day later they reply telling me that this was the best they can do and I should reply within 48 hours if I want to accept it. WTF? I wrote a friendly reply asking them to please reconsider since I had sent in my entry in the very first week of September, etc, etc. and was hoping they found an alternative. No reply. VERY bad service and definitely the last time I will shop there. I have plenty of miles accumulated with my Lufthansa Miles&More card, but this is not the point - it is a matter of principle and I feel cheated. I am pretty certain that what did me in was the fact that I did not enter a second (paying) person, which obviously is how they monetise the whole offer: one passenger travels for "free", the second is a paying one. Did you participate as well and if so, what was your experience?