Fair enough but that does not excuse the fact that they basically offered no help after the fact, to rectify the issues the customer had after they tuned it?If the knocking is due to a loose hose should be easy to spot. Does it only happen over rough road or bumps, or is knocking all the time / at idle? If the latter then you may have a problem.
Not sure we can blame the shop yet. You seemed to have had issues when you swapped the intake yourself, sounds like it was never sorted properly. Hopefully its a simple fix.