Cell Unlocker, www.cellunlocker.net
I have a Huawei Ascend G7 and took me months to unlock. I tried a few online services and even going to the carrier's shop. Nobody could give me unlock codes and made me wait for weeks.
FINALLY I decided to use Cell Unlocker services and in less than 24 hours I had a working unlock code. Not only that but their customer support service was quick and reliable.
5 out of 5 stars. Totally recommend it.