Chill guys!
Its just a Job. You join as an FO. Merit/vacancy, not seniority gives command. Seniority gives access to the review board. Its not automatically guaranteed when you join. As someone already explained. If you have 5 aircraft all pilots will be captains when there are 10 shinny aircraft. If you join when there are 100 aircraft in the fleet, expect you number to be call then there are 200 aircraft. DEC have been around for at least 5 years. So, I assume they were here when you joined.
EK is a business. Basta! Its wholly owned by a guy who also happens to own a country. He doesnt need to be nice these days. When the times turn, he will give us a nice bonus and we will all wag our tails again.
Thats my honest opinion.