Using depression as an excuse

Someone keeps using it as an excuse to make fun of me, not attend classes just bunk off on xbox and not get any sanctions for it but I get told off if I did any of them. Its not fair, just because they a feeling a bit sad ahhh they get to stay off and get there arse kicked by staff with the sympathy card. I know mental health but its disgusting and embarrassing when people think they can use it as an excuse to put others down or not get a job or just be a ****. Someone's doing it to me and I hate it so much like they aren’t special and they should all be treated the same they can't blame it on depression.

Some guy at Barton was being a duck head to my mate and took the piss out of him then said ooh I have been doing this be ive been depressed, ooh I'm sorry, im sorry you are a little snowflake ooh dont cry you baby and stop playing the victim card.

I'm sorry I just wanted a rant because I just have got in from college

I don't exactly understand your post, but nothing of these looks like someone having depression.

The actual depression is a serious anormality in brain's work, particularly a neurotransmitters deficiency.
People with depression don't just feel sad, they feel weak, tired, unmotivated, easily get frustrated by simpliest tasks which normally shouldn't be a problem. They might be suffering from insomnia and memory loss. Sometimes depression even gives cancer-like symptoms (somatising depression). It's not a condition you get for a moment. Episodes of depression last from weeks to months, and as a person who's been suffering from it for years, I can't imagine it motivating me to make fun of someone. I might be more harsh in my opinions if I'm not yet in a state so bad I can't talk at all, but that's it.
If anything, depression makes you too demotivated and tired to do anything. The only thing that can cause some more active action, is that in depression a person has clouded judgement, overestimates meaning of some things, and may easily get triggered into fury, but it doesn't apply to everyone.

Usually in depression you get angry when you get frustrated by some work that's getting too hard because your brain doesn't work properly, or when someone shows you some disrespect you were expriencing earlier for the long time, you did not have a chance to repay compliments, and the old hidden anger bursts out. But it doesn't apply to everyone. Generally people suffering from depression are rather withdrawn, migh be easily triggered and more extreme in the way they see the world, but making fun of other people sounds unfamiliar, and indeed like an excuse from someone who's never even had depression.

No one's going to know if this person actually does have depression but either way, it's not an excuse to treat people badly