Contact them and explain the situation and maybe they will give the code but they are the only people to get it from because of it being a RM-225 type.
To be able to unlock the models listed above (not the BB5 section) you can get the code from your network provider or by taking the phone to a shop / Pro to be unlocked directly.
It's all in the IMEI# that tells me the story of the phone. If yours unlocked, it was because it was not the RM-225 type. The way you can check the type you had would be to press *#0000# and it should display what RM- type you have and I can assure you that yours will not say RM-225, it should be RM-75,76 something like that.