Discovery V6 Smartphone mtk6572 SIM card problem!

[subwoofer2406]

Hello!

One month ago I ordered a Smartphone "Discovery V6 Smartphone Ip68 Dual Core Android 4.2 OS Waterproof" From China's web shop AliExpress ( http/ ).

Two days ago the phone arrived. I put my SIM card in the SIM slot (usually in slot 1 (Dual SIM)) , and launch my phone. Phone turned on and i entered PIN code and normally open my telephone.
I waited few minutes, phone to set up. it has showed that i entered SIM card in and also it showed my mobile operator (Tuš mobil). But the signal icon never turned on (it has stayed grey). I didn't know why so, so i went to directory (which appeared to be active) and tried to call someone (my friend). it didn't work. It has said that there is no signal (there is full signal in my city).

I really don't know what to do... I even went to mobile operator and changed my SIM card but the signal icon and possibilities are the same as there was before. I also tried to put the same SIM card in my old phone and it worked perfectly.

Does anybody have/had the same problem as I do at the moment?
I would really appreciate if anyone could help me or give me any adivce

Thanks for your time!

 

[subwoofer2406]

Today I read on a random forum, that the phone may be locked. And it supposed to bu unlocked to work normally.
So does anybody out there knows what's the procedure to unlock it?
I would really appreciate if somebody would help me, ot give me an answer!
Thanks in advance!