I used to be IELTS invigilator there. They called me in when they were short of staff.
They never provided proper tools for the invigilators, eg. poor-quality pencil-sharpener, etc. despite continuous complaints. They also paid less than they should by calculating wrong working hours. When you sent emails to check they simply ignored. That's why they keep on recruiting new staff because they couldn't keep the team!
Their management of IELTS is also problematic. Candidates could never find them on phone. Theyaslo arrange the speaking and written tests of IELTS at different locations, and many candidates missed the test because of that.