Product: Payday loan, title loan, or personal loan

On XX/XX/XXXX I took out a loan with Upgrade for {$12000.00}. 
My payments were set to start every XX/XX/XXXX of the month starting XX/XX/XXXX. This did not coordinate with my pay date for this month so I pushed out the payment 5 days to XX/XX/XXXX. Besides this payment, XXXX and XXXX payments were both made on time per the scheduled. Between these 3 payments, I have made a total of {$2900.00} towards the principal balance in multiple payments. {$200.00} XX/XX/XXXX ; {$2000.00} XX/XX/XXXX ; {$100.00} XX/XX/XXXX ; {$200.00} XX/XX/XXXX ; {$150.00} XX/XX/XXXX ; {$300.00} XX/XX/XXXX. On XX/XX/XXXX I called in to make the {$300.00} principal payment and then I called back and spoke to XXXX about a question I had on payments. I explained to her that the interest on every scheduled payment should be going down every time and more should go towards the principal balance every payment instead of more towards interest. Especially because I am making extra payments. I had to explain this situation to her multiple times because she did not understand me. I explained to her that for my XX/XX/XXXX payment of {$420.00}, {$290.00} went towards the principal and the teaming towards interest, on XX/XX/XXXX {$340.00} of my {$420.00} payment went towards principal and the remaining {$77.00} towards interest and for XX/XX/XXXX {$330.00} went towards my principal and {$85.00} towards interest. I explained to her that I was confused as to why more went towards interest for XXXX vs XXXX. From XXXX to XXXX payment the principal increased and interest decreased but from XXXX to XXXX this was not the case. I was just confused as to why less was going towards the principal for XXXX. XXXX placed me on hold for a few minutes, came back on the line only to say she didnt understand my question. I repeated it again and explained to her again. She put me on hold again for a few minutes and she came back to tell me she had to escalate this to the payment department & someone would contact me within 24 hours. I was on the phone with her for about 20 minutes and received no proper response. I didnt receive a call within the 24 hours she specified so I called back on XX/XX/XXXX and spoke to XXXX. I explained the situation again to XXXX and it looks like the notes XXXX inputted were incorrect as he thought I wanted to know why my balance wasnt going down. He placed me on hold then came back & told me that the reason for the interest being higher XXXX is because of the calendar days and because I made my first payment late. I informed him that this made no sense as then my interest for XXXX shouldve reflected that not XXXX. He placed me on hold again & said he was going to transfer me to his supervisor to better explain. He did not transfer me over. And he proceeded to tell me that because I paid more towards principal in XXXX versus XXXX my interest was less. I explained to him that my interest should keep being less every single payment especially because Im making extra payments frequently so it doesnt make sense that Im paying more towards interest in XXXX when my balance is decreasing. I then proceeded to ask him how much of my {$420.00} payment for XX/XX/XXXX will go towards the principal and interest since I have paid {$450.00} towards the principal for XXXX so per his logic, more should go towards the principal my next payment. He placed me on hold then told me that he didnt have those numbers and couldnt tell me how much of my payment will go towards the principal and interest but that I could calculate it myself using an amortization calculator. This frustrated me because how is that a loan company doesnt have break downs of payments. How do they expect customers to calculate this themselves? XXXX told me he can provide me with the interest to use to calculate the payments but again this was not the point. There are so many people out there who have no clue about loans or even using online calculators but they expect them to do this on their own? This is not okay. As a loan company they should be able to disclose all information about payments and break down. The explanations they gave were weak and showed a lot of discrepancy which is not okay to a customer. I realize its only a few dollars but this is still not okay to a paying customer