What causes me concern is that the friend who got you the job has shafted you.
Perhaps he expects you to take him for drinks as a reward for getting you the job - I don't know.
Be that as it may, a distressing situation has been engineered by him and its making life difficult at work.
Employers are supposed to ensure that the dignity of employees are supported in the workplace.
Normally this is seen in the context of the employer not doing things to undermine that dignity, but this is about fellow employees disrespecting you.
In my opinion employers should ensure that that morale of the workplace is good and employees support each others dignity and mind their own business about out of hours activities.
On the other hand, you are giving an outline of what can sometimes be a very complex situation - relations in a workplace.
With so many people under stress with job-related issues, its easy to single out one person to be the butt of thoughtless remarks.
Sometimes people are trying to lighten the tension, but it makes things very difficult for the object of the humour - you, in this case.
If you firm has a HR representative or a shop floor manager or line manager I would refer the matter to them.
If you escalate this and bring some sort of action through a rights commissioner you may make your situation worse.
However the wit you describe seems to be pretty low-level and sometimes just ignoring people is the best course of action.
I wish I could advise you more.
ONQ.