Hi lazy,
I was your daughter once, to a certain extent. I'm white and my husband is Pakistani muslim. We've been together 8 years (we separated a few months ago, long story) and it took 4 of those for him to even tell his family about me. We literally had to duck and hide if we were ever out in public. It was awful and I hated it. He was too much of a coward to tell them, but I loved him so stuck by him. It got to the point where he was part of my family but I didn't even exist to them.
Turns out I got pregnant and met his mum for the first time when dd was a week old. It took another year and a half before I met his dad and siblings (except one sister who I was introduced to shortly after dd was born). For me the wait was worth it, they welcomed me with open arms and I'm part of their family now. We all get on great. Which is how it should be.
From your point of view, it's a good thing he's not lying about your daughter to his family and going behind their backs. But the way in which you have been treated is just awful, and not something which anyone I know would ever condone.
You see with Pakistani's (the ones I know anyway) it's all about how they look to their neighbours. And their son having a white girlfriend is shameful to them. Sad but true. They seem to have this 'acceptance' culture and deem it to be a privilige to be accepted into their family. Sorry that's a very general sweeping statement, but that's how it is from my eyes.
If your daughter and her boyfriend are serious then he needs to man up, the only thing being boyfriends/girlfriends aren't permitted in Islam, so marriage would need to be talked about.
If I'm completely honest I would tell your daughter to run for the hills. I have known many a girl be in this position and it doesn't change. At lot of my friend's husbands have had to take on second wives just to keep the family happy.
I hope this helps you a little bit, you don't have to put up with being spoken to like that. We are all equal, not one of us is any better than the other.
And sorry if I offended anyone.
Good luck and keep us updated 