Spirits Kinda Broken

Hey guys. So I work for a digital marketing company in a hybrid position (I open and close deals). As an opener I basically warm up leads and send them to someone to close, basic stuff. As for the closing side, I only sell to Portuguese speaking business owners (I speak fluently), going through the whole sales cycles and doing customer service for them as well since i am the only that speaks that language.

But anyways, because it's not a common language, I essentially get paid a slightly higher percentage when I close a deal but get no residuals in terms of monthly payments. I do on the other hand get hourly (minimum wage, $15hr) and commission, which as a full time closer you get one or the other, so it's nice for me. 

Here's what's bothering me though. Almost every paycheck I've received, the commission has been wrong. I've done things to make checking and comparing easy, but I feel that I shouldn't have to check every time to make sure I didn't get stiffed. Most recently, I hit a personal record in terms of deals closed in a pay period, which was impressive enough where other closers asked where I was getting leads. Keep in mind I only close in Portuguese and literally everyone who speaks it owns a business lol. But, I was happy about my pr UNTIL I saw my paycheck and noticed I was stiffed.... 

When I brought this up I was told they would compensate a small part of it to make it up but that's about it... Not the whole, agreed upon, amount..... Otherwise I'd have to take it higher up which could cause problems because my opening numbers have dropped due to how many leads I get. 

Maybe I'm just upset about being stiffed, but I feel like I give access to a huge untapped market and do the customer service on top of that so worrying if my pay is correct and having to go out of my way to TRY and get the actual amount, isn't something that I should be having to deal with. 

Sorry for the rant hahaha, but any advice/thoughts are genuinely appreciated.