I just had my cell phone cloned yesterday. End of the day, my phone lost signal suddenly. I thought it was a problem with my chip, so I decided to check that on a store and buy a new one next day.

Today, after I recover my chip and number, I started to see the mess. Someone used my number to send message to all my contacts on whatsapp, asking for money. Also, I had some contact info changed on the bank broker, which is really serious. I do not know what else is compromised, and I'm truly worried about it.

Someone has some good tips for improving security while using cellphones?