It's against Amazon TOS to contact Amazon's customers outside the Amazon messaging system, and they are really heavy handed against sellers breaching this.
If you complain to Amazon that the seller is contacting you outside the Amazon messaging platform and harrassing you, then Amazon will close their seller account.
Alternatively you can threaten to report them to Amazon for this and they will go away.
It's against Amazon TOS to contact Amazon's customers outside the Amazon messaging system, and they are really heavy handed against sellers breaching this.
If you complain to Amazon that the seller is contacting you outside the Amazon messaging platform and harrassing you, then Amazon will close their seller account.
Alternatively you can threaten to report them to Amazon for this and they will go away.