Wonderful customer service experience from Matrix Sim Cards. I was delivered my UK number 3 days in advance but when i tried checking it at the airport for signals and usability, it flashed registration failed. Luckily there was a Matrix counter at the delhi airport and without even asking me a million questions, the guy behind the counter replaced that sim with a fresh one and emailed his backend with the changes made. Its rare to experience such from a telecom company! Really appreciate