Hi im new here/TALON P ?

First off hi im new here and fairly new to pcps I have a freedom 8, 25cal marauder and just got a talon P yesterday unfortunately the tank would not thread on to the collar its a spin loc tank I did have the set screw removed and it would not thread on so I remove the collar and tried to thread it on that way still a no go it seems like it wanted to cross thread I did not use much pressure … so I had to send the tank and the collar back but was just curious if this is a common problem and also where do you buy factory replacement parts like this because I can’t find them anywhere Thanks