In case your SIM card is blocked, you will need to enter your PUK code to unblock the SIM Card
Unblock your SIM with your PUK - The PUK code is a number unique to your SIM card. It is used to prevent unauthorized use of your account, and keep your SIM details safe. You’ll be asked for your PUK if your PIN code is entered incorrectly 3 times.
If you don’t have your PUK code,dial 199 and select the relevant option.
Entering your PUK code
Enter the PUK into your phone when asked.
You’ll be asked to enter a PIN code, twice. It needs to be between 4 and 8 digits.
You’ve got 10 attempts to enter the correct PUK, so be careful. After that, your SIM will NOT work, you will need to get a replacement.