Certificate issues

My experience with Rostec technical fet college was very bad ,they didn't keep their promises, I was a student there and my file was supposed to be taken to the assessors and it was left behind by my lecturer. Now they request R1000 for me to pay them so that I can get my certificate. I've done my part by paying school fees and the R1000 they want is sort of like a bribe to make my things go fast . Please help , I'm a student and they're taking advantage . I'm scared of them