There is no pros in working for an unprofessional and unethical company as such, but if you need a reason to get employed it could be mere desperation to get a job. Or in between jobs to get some income while searching for jobs.
Cons
Most of the time very marginally legal, unprofessional and unethical labor practices.
Never pays on time, and most of the time there is no honoring of verbal or email discussions.
Management makes lots of promises over phone but never follows through.
Once you get rid of the contract with BestITExperts which isn't easy, you will see a huge good difference when dealing with any other company.
Cons
You don't get paid for the work that you do.
The business model is as simple as this - they give false verbal promises to trap both consultant and a client on their contract, and once trapped they short pay or simply steal money from consultants. There are not only moral issues, but there are violations of the law because they violate terms of the contracts. Stay away