there's always a small window where your ECU will adapt to the new tune and smooth out a bit, but you should be able to feel a difference immediately. you should be boosting a lot higher right off the bat. Do you have a boost gauge or VCDS?
i noticed GIAC immediately
Id ask for your money back. Think they are taking you for a ride. It should be largely noticeable.
I noticed apr tune and zero traction right away.