Distorted

I have had a really hard time in the past getting my digital pictures professionally printed for me. When I print the digital enlargements at home I can get the picture to look right but I have a hard time with the quality. When I take them into a professional printing company the quality is great but the image is distorted. I would not mind sitting down with a person to go over exactly what it is I am looking for in my print but I can not seem to get the level of customer service I am looking for.