how do i remove unknown voicemail message bank?

i bought a samsung J600 phone from United Arab Emirates and came back to sydney 3 days ago.
i used my old sim card from a vodafone locked phone in the new one, and it sends and recieves txt and calls with no problem.
i have no message bank set onto my number, but everytime someone calls, the phone rings for 10 seconds and then diverts to an Arabic message bank.
i dont know how to turn it off.
ive tried to remove all call diversions, and deactivate my already deactivated message bank. vodafone says my voicemail is deactivated but the Arabic message bank is still there.
even when someone leaves a voicemail in this message bank i cannot retrieve it.
how can i remove this ASAP?
please reply!
thanks