Hi there,  I buy certain things from Lazada when needed and generally I find  the service good. The problem I have is that when I log in I'm asked for my account  validation by SMS. This doesn't work because I don't recognize the phone number shown. Consequently I can't validate my account or change my validation phone number to the correct one.

You're screwed. Create a new account with your correct phone number.

9 minutes ago, Mason45 said:

Hi there,  I buy certain things from Lazada when needed and generally I find  the service good. The problem I have is that when I log in I'm asked for my account  validation by SMS. This doesn't work because I don't recognize the phone number shown. Consequently I can't validate my account or change my validation phone number to the correct one.

if you use Google, scroll down and click that icon, then account name, then continue...done