Do you think I should approach my friend about getting the payment I've been expecting from their wedding
Why are you expecting a payment?
Because it's my right, I split the bill with them
Have you told your friends that you will be splitting the bill instead of treating them for free? They might be under the impression that they are getting it for free and you may look like a very bad person charging them for it when they were expecting things to be free.
Fuck you man.
I apologize, I just want you to understand that your friends may think that they are being forced to pay for something that they never asked for. Communicating your intent to your friends may be a good idea in this situation.