This is quite mysterious, I do not suspect anything illicit but technology is so complicated nowadays would we really know.

I am currently in US though I think my location is irrelevant.  I have a pre paid mastercard which is very convenient for travelling as one can spend in any currency with no conversion fees, appreciate they make money by other means but using is simple.  Phone app allows balance checking and authorisation etc

To log in I have to use a password, then I am asked for a 6 digit code which is sent via text message to my phone.  This worked fine three days ago but now, instead of a text giving me a 6 digit code I get a text from amazon saying they are trying to deliver a parcel.  I have tried this many times, each time an Amazon text. 

I've uninstalled the app, cleared the cache, cleared program data, restarted the phone but still, instead of 6 digit code I get a message from Amazon about a parcel.  There was an Amazon parcel that sent me that text three days ago, due to a problem that required a security code it was delivered at the third attempt but how this Amazon text has become associated with my mastercard I have no idea.

I'm liaising with the card company who said they had arranged for 6 digit MFA to be sent to whatsapp but so far no luck.  Am awaiting a call back from them.

Technology, sometimes I do wonder how it works at all.

Geffers