Then for the love of God, if there is any truth to that, pass on to us just one unwritten tradition that was passed on by the apostles, with proof of course...
“..one unwritten tradition that was passed on...”
We have been explaining this over and over to deaf ears. The tradition of the Eucharist is both written and handed on. In John 6:53 the command is written, however - not all the liturgical instructions as to how to do this (John6:53) sacrament are written in the bible, that is the part that is handed on.
The Didache contains the instructions as to how to accomplish Jesus’ commands in John 6 - that is some of the proof, of course. Most important is the unbroken proof of the mass being celebrated since the very beginning of Christianity, without ceasing. The early Christians were persecuted by Rome for it, as well. See St. Ignatius of Antioch’s very early writings that have been preserved since antiquity. He died in 110; he was martyred in Rome, and he wrote explicity about Christ’s real presence in the Eucharist, proof that the early Christians had the mass from the beginning.
The sacraments are the handed on traditions, and they are written about in scripture. The apostles knew that the Christians were carrying out the sacraments at the same time as reading about them, and their catachumens would have been doing both and fully understood both. The early Christians began as a Jewish sect, and the Jews ALWAYS had an oral as well as a written tradition. The ones who became Christian continued this practice when they became Christian. This is how religion was practiced - first as oral tradition and then once written down - both. The act of writing did not cause the oral traditions/rituals to cease.
The bible does not say that it is itself the only source of truth.