How to unlock my iphone 4 (orange)?

I have an iphone 4 on orange i called up t mobile because i have a t mobile sim they said they can do it and made me top up £25. Later i call them they say sorry your on orange you need to be an orange customer. Thats £25 down the drain, i'm not the original owner so i can't contact orange plus i can't contact the original owner either, i think they changed their number.
I tried to go to unlock shops they charge 80- 90 quid i can't pay that much. Has anyone got any other ways, i don't want to jailbreak i want a permanent unlock and please don't suggest me sites that do surveys that require personal info.

Do you need to unlock your Orange locked iPhone 4?
If you need permanent unlocking solutions for your iPhone 4 visit http://www.theunlockarena.com/apple-iphone-4/rs5wp9/ Here you can unlock your network locked iPhone 4 using Remote unlocking method. It's one of the best and safe way to unlock your iPhone without jailbreaking.Once unlock your iPhone 4, you will be able to swap your network carrier to T-Mobile from Orange without having any problem.