Oil Leak through Breather Pipes

Hi there, wondering if anyone has experienced or can help me with this. About 4 months ago I had fitted some extended breather pipes up the snorkel for the autobox, axles and transfer box and they have been working fine. (1995 300tdi auto)
However yesterday I had the transfer box oil changed and ever since oil has been leaking out of the top of the breather pipes. I have only been driving it a few miles to work and back and to town but its still coming out.

Do you think this is just a case that the garange overfilled the oil or a more serious problem? There are no other leaks. The fact that oil is coming out indicates that there isnt any blockages.... Do you think it just needs to spit out the extra oil and all will be fine?

Any suggestions would be great!

I'd say too much oil. You can check this yourself by checking the filler plug