Yes, the agency in the Philippines will be mad if you pull out, because they would have earned commission on placing you into the job.

I think it's not too late to pull out now.

If you have signed the offer letter that is not legally binding. You are only an employee once you have arrived in Qatar and signed the full offer letter.

If your papers haven't yet been processed then you have every right to pull out because that's a disgraceful offer.