My passat wont start HELP!

So my wife has been planing a trip to disneyland for a few months for our daughter and we had just purchased a 03 passat and ended up taking it back two weeks later cuz it ended up needing 2000 bucks of work for two cats and o 2 sensors. so anyway we ended up getting a 05 passat 1.8 T gas auto trans and put like 400 miles on it. so i get in one day and the motor wont turn theres only one click. i got all power in the car lights, windows, radio,ac ect and no turn no matter how many times i try. so i went and got a new battery and everything was tested after installation, everything was normal and so i looked at the starter and took it to auto zone. they said it was good so i put it back in the car and it started 3 times then the same sh** NO TURN i got all the power all connections are tight and so clean u can eat off them. so i got it in a garage downtown and there telling me that there not going to get to it for another day so any advise would help or if u have any q’s please call anytime 916 595 2116 sean a from west sacramento,ca

my best guess would be starter/solenoid I think it is 1 unit.