s3 mini problems

[eddiemac]

hi guys,
i have spent 5 days trawling forums and the net to try and solve my problem,
i have 2 s3 mini i8190n phones,one i found and it works perfectly except it has been blocked by the service provider,it receives a perfect signal but cant be used,
the other works perfectly is not blocked had it unlocked by the provider but it wont pickup a signal i am getting circle with line through,
the imei no is there,
both are using the same firmware modem baseband etc,
when i go into the service menu on the phones the blocked phone shows info,the duff one shows no service,if i use back key and check the settings of both phones the setting are totally different,
can anyone tell me away to get this phone working again as im pulling my hair out,
cheers