Vista - I've been banned from my network?

So I have a dell laptop running on VISTA. My brother whose really tech smart, does not like me, so he's banned me from the network, he even siad so himself. I KNOW he's banned me, because I would give him like 20 dollars and then he'd go into his room where his computer is, and do something, and all of a sudden my internet would work.

So my question is....How is he Doing this? And how can I get through his block?

My brother is ruthless and merciless so he will not come in, in I just pay him...ONCE. Or do anything good to him.

PS: First I thought he was blocking my ip so I tried changing it and there was NO luck. But I found out online about MAC addresses and I thought maybe that was it. So I changed my MAC address and I was able to connect, BUT I had no internet access. Vista said I was connected [5 bars] but no access. There was still the two computers symbol in the tasktray but NO globe on the computers.

Get help from your parents.

If he bans you as has been said speak to your parents.
What he is doing is also blackmain and bullying, mention this to your parents.