Given my exams are over I like pointless debates
Yes, as a noun on it's own I'd use raise. I got a raise, I'd like a raise, and so on. But when "pay" is included so you know what it is that is going up then I use rise.
Apart from anything else, let's imagine me talking to you about the recent increase in pay I (didn't actually) just get. I go first:
"I got a pay rise the other day"
"Oh so you pay raised?"
"No, it rose"
"But that's the past tense of "rise", not "raise""
"Exactly. Maybe it's just that you're English and I'm American"
"This argument is dull. Wanna go play BF2/HL2DM?"
"No, because Steam SUXORS"
"I'm glad we got back on topic"
You're stupid, uneducated, and lack basic social understanding. But hey, at least you play video games...
Right back at ya!