The slave must obey his master’s orders if he prevents him from Friday and congregational prayers because he belongs to his master and it is not mandatory upon a slave to pray in congregation but he must pray on time.
As for you, it is mandatory for you to pray on time. If they prevent you from praying in the masjid, they can’t prevent you from praying in the office which doesn’t take more than 5 minutes.
They can’t prevent you from going to the toilet and a lot of companies allow their employees to go for a smoke or a coffee break.