I have no clue what your [censored] was, but since I worked in the autoparts biz, I know the 90% of the dipshits behind the counter are absolutely useless. If it isn't in the computer, they don't have it and can't get it. Hell, I had to teach a kid how to use a book at my local AAP.
YOU need to to armed with a few things when you go into ANY autoparts store 1) General knowledge about your vehicle. Don't point to it and say 'that one' or anything. Know your engine type/size/vin designation, etc 2) get a part number either aftermarket (know the specific brand if you do that) or the OEM part number so they can cross reference it 3) the actual part itself. Otherwise, the only person to blame for not getting whatyou need is yourself.