Unlocking a second hand iPhone?

[JamerTheProgram]

Hey!
I bought an iPhone 4 off of eBay factory locked to Three.
I now would like to unlock it if possible. The guy who originally owned it said that hes still using the sim that he used in the phone I bought off of him and he said that he cant do the unlock because he doesn't want his sim to be terminated.
Is there another way I can do it permanently? Im open to doing some jailbreaking as thats my plan anyway.
PS: Can Jailbreaking give you the no signal issue?
Thanks!

 

[Applejuiced]

Jailbreaking and unlocking are 2 different things.
Shouldnt you have figured this all out before you bought an iphone that you cannot use as a phone?

 

[Baggio]

Applenberry.com does permanent IMEI unlocks in the UK. It's $70 USD.

Another option is the gevey sim adapter. Applenberry sells them as well.