But not in your liturgy.
the symbol of the Faith they issued is the Nicene-Constantinopleatin version
"They"? Where did Ephesus issue the new version of the Creed? The only one quoted in the Acts is the Creed of Nicaea.
creed being that which the Nicene fathers believed
Ah, I see. I thought you were upholding the old Orthodox position (i.e. the one defended by Mark of Ephesus) which was that it referred to the words themselves. Needless to say, since the filioque was believed by the Fathers at Nicaea and Constantinople, it is you who have departed from their creed, unless you want to claim, absurdly, that Sts. Athanasius, Gregory of Nyssa, Basil, etc. did not believe in the creeds which they assisted in framing.