Unlock my iphone 4

I sold iphone 2g, and bought 3g, after 1.5 years my 3g was broken, so I bought iphone 4g, and it is locked. I can't call, I can't type sms, nothing.. I'm two months without phone. My phone is locked to swedish telenor carrier, I live in lithuania, for me is not imposible to travel to sweden from lithuania. What should I do? Sell iphone 4 and buy other phone? Or maybie can you unlock it. I like apple products, I have macbook, ipod and I had iphone 2g, 3g, now 4g. How I sayed I like your products and I don't want to buy other phone. Please help me, or tell me what should I do?