I agree with you Zewp, that would not make good business sense.
In fact, when I went on Thursday past, they did not inform me of the special deal on frames either. The assistant helped me deciding on a frame and then worked out the quote with lenses etc. Only during that time did I ask her about a frame special advertised on their website (obviously I made sure the one I picked fell in that particular category).
So maybe the staff are told not to mention the special unless the customer asks about it. Who knows, right?