Hello, can I unlock my w715 with XS++?

Hello, I have two SE phones, both are locked to Mtel Bulgaria, one of them is W715, the problem is that I can't find suitable Custum File for my country. Can someone tell me if there is way to unlock this phone and which Custum File I have to use? Otherwise I've downloaded this two SF: W715_R1DA029_MAIN_HUTCHISON_NR_RED52.fbn and W715_R1DA029_MAIN_HUTCHISON_NR_RED52.mbn.
I tried to flash my phone with Wotan Client, but they have only Mtel mobile operator for Bulgaria.

Thanks in advance! :)

No you can't unlock with XS. Only paid unlock with Omnius.