Tascam is pretty helpful with problems, they've been responsive to me so far. You might e-mail them from the Tascam web-site, in fact you could try
Custserv4@tascam.com or
Custserv4@teac.com one of those is right!
Got a good computer tech/supplier in your neighborhood?...
I know what you mean about the shape of the plug- it's kind of square at one end with two little points on top. Poor form on the part of your seller, sorry!
Rog.