What if I reject the job offer where the salary is less than initially offered by email?

Greetings.

My name is John. An employer offered me a job by email for AED 3000 and he asked me to send my passport copy, pictures and visit visa.

But he prepared an offer letter from the Ministry of Human Resources and Emiratisation (MOHRE) carrying only AED 1000 and gave me to sign it. I have rejected his offer, told him that I can't work for him anymore and haven't signed anything else with him.