Avoid Lebara

Piperoscar

I have used Lebara for several years and recommended them to many people. 
Last Thursday I got a notification asking me to verify a payment of £495 from my Tsb account to "Lifestyle" (who?). This never went through as I have no money in that account! 
I later found that my sim had failed and my Tsb app was blocked.
I drove 10 miles to my nearest Tsb branch who told me I was blocked because the criminal with my number had failed the security questions but he had created for me a new email address and London street address (which they would not tell me) and applied for a loan. This was denied and they shut down all Web contact. 
I do not understand how easy it was to port away my phone number without telling me.
The same thing happened to my brother using Lebara,  are other phone providers the same or is it just Lebara to be avoided?