Blocking the IMEI of a phone is done by the original network provider. This is not a problem as the phone can still be unlocked at a later date.
The IMEI block prevents the owner from using the phone in the normal way and will start to experience a progressive decrease in the phone's functionalities.
They will most likely be able to access the internet and send text messages, but be unable to make calls.
If you insert the phone's SIM card into another phone and you have coverage, but can't get any coverage with it inserted into a recently unlocked phone, this means the IMEI has been blocked by the network provider. You will need to contact them to find out why your IMEI has been blocked.
Even though the unlock instructions we sent you are valid, they may not work on a phone with a blocked IMEI. doctorSIM does not issue refunds on requests for phones that have their IMEI blocked, as this block is unrelated to the unlock service provided by doctorSIM.
It is the responsibility of the owner to know if their phone's IMEI is blocked prior to making a request to unlock their phone.