There is no way to bypass or hack the iPhone to go beyond the iCloud lock. No service will be able to unlock the device for you, no matter what they promise, and you will be just throwing your money away.
There is an exception to this rule, and that is if you have the original receipt from Apple with the serial number of the device on it, Apple may be able to unlock it for you. However even that isn't guaranteed.
If you purchased it from eBay or Craigslist, we recommend getting in contact with the seller to see if you can return it to them and get your money back.