Computer Printing Problems

I have created a polka dot pattern (.125 inch) on Photoshop CS6. When I print it out at home on a 8.5"x11" sheet it comes out perfectly. However, I need larger print so, I contacted Fed Ex to make them for me. The issue is that the dots come out a bit smaller than .125 inch. What is the problem and how can it be fixed?

Lack of margins? PPI issue?

I have spoken with a fed ex team member but, they do not know what they are doing.