Truthfully, my most recent unlock is probably the 25th unlock I've done with CellUnlocker.net... they did deliver within the timeframe of 1-72 hrs (it was a bit unclear if was in fact 1-72 hrs or 1-72 business hours), but I did receive the instructions etc. and the unlock worked the first time I attempted (it was very easy).
Additionally, the instructions was very clear and concise and all possible scenarios were covered in the instructions I received.
In conclusion, CellUnlocker.net is one of my 3 'go-to' unlocking services I trust in my business for some of the lowest prices and really quick turn around times. I highly recommend them.