Just for clarity, the negatives are already "developed." What you mean to say, and what you should ask for when talking to a photo lab technician, is that you want reprints. Reprints means that you have developed negatives and that you want additional prints from them. Normally reprints are different than saying that you want enlargements. The term reprint (from the perspective of a lab technician) means that you want standard 3 1/2 " x 5" or 4" x 6" prints as opposed to anything larger which would be considered to be an enlargement.
To answer your question more precisely, just do a search for "photo labs near me" and that will show you where to go. You usually don't need to mail your film off to a lab far, far away, especially if you live in or near a metropolitan area such as London, Rome, New York, etc... You don't mention where on this great Earth of ours you live, so I can't tell you where to go.