Upvote:1
The letter is quite clear. They did not see any evidence that supported your assertion that you work for Pfizer. They also did not understand that the nature of your employment with Pfizer changed in 2016.
Submit a new application, including evidence to show that you work for Pfizer as an employee, that your employment on those terms began in 2016, and that you worked for Pfizer before 2016 as a contractor.