I have a doubt that Nokia Unlock Service MIDlet can not be used to none-developer version Nokia 6131 NFC phone, isn't it right?

Last week I met a problem of "no server connection" while using unlock service,
later, I solved this problem by downloading a new "internet" settings from nokia site.
But finally a new problem came out with below
"Unlock process imcompleted!source:
Unlock process has been executed on this phone."

I bought Nokia6131 NFC phone is not developer
version, so I doubt that the unlock serice maybe
not for this version.But in Nokia's related document not mensions that.

Can give me some advice? is it no way but rebuy a
Nokia 6131 NFC phone with developer version if I want write some data into secure element?

Thanx a lot.