I would have to come to the defense of lfs, first and foremost it is the consumers responsibility to know what they are asking for. For sure some salespeople misrepresent and that is reprehensible. On that note, I must wonder was it done on purpose or out of ignorance. If done on purpose the person is a smacktard who needs a kick in the wee wee if out of ingnorance can they really be held to blame. After all they most probably are not making the highest of pay and have many things that overwhelm them as well as have their fair share of people taking it out on them when they come into the store and multiple incidences of S & A tend to make people seared in the care area.
On the other side of the coin, I have some domino damsels in my 75g reef tank that people told me to get out. Even going so far as to call them demon damsels. I have had them for over 1.5 years and they mind their own. Presently they are with a mated pair of clowns who gaurd their anen fiercely, a tomato clown, a black and white clown and an engineer goby.
I really think the key to a good tank is the way in which the rock is laid out.
Sorry to hear you had a bad experience. Have had a few myself, like the time where the fish dude told me in a huff that since I called newts salamanders I must be unable to care for them, besides I did not even know the scientific name for them so he said he would refuse to sell them to me.
At which time I politely informed him that the petstore tank was not hard to reproduce and that I did not need to know the scientific name to care for them as I had asked my last time in what it took to care for them. These were also a pet that my then 6 year old son was totally in awe of and as his father, it was my intention to fulfill my sons wishes.
In speaking with the fish dude, I asked him how many tanks he had running. It seems that he was more of a herp dude and had very little in the way of active water. At this time I had over 27 tanks running totally almost 2500g with over 100 empty tanks of various sizes in my basement. I told him in no uncertain terms and in very clear words that he was not as important as he thought himself to be and that I could easily have a tank set up in less than half an hour that would be far superior than the central sump system tank they presently have them in and also asked him who he thought he was to deny my son these newts!
On the way out I had a short talk with the manager. I reminded her that they were not the only pet store in town. I used to shop there minimum 2/week and it was not unusual to drop $150-$300 per visit sometimes, though most visits were in the range of $25-$50. Still add it up and as a business person selling food, people vote with their feet and their wallet. Now most of my visits there are to see if they have brought in a unusual fish or to let my kids take some time with their animals most of which are open for general public to interact with.