Product: Payday loan, title loan, personal loan, or advance loan

I am complaining about predatory lending practices by Goodleap. I applied for a loan from Goodleap on XX/XX/XXXX to pay for a new air conditioning system. The loan amount was {$9800.00}. What I remember from the Goodleap welcome call was that I had an 18 month promo no interest period, my first payment was due XX/XX/XXXX, and I needed to pay the loan off in XXXX to avoid paying interest. I have been checking my statements regularly and was shocked when I opened my XXXX statement and say that I now owe them {$12000.00}. I called their billing department on XX/XX/XXXX, thinking this was an error and planning to pay off my loan in full, and learned for the first time that I needed to have paid the {$9800.00} off before XX/XX/XXXX to avoid the interest. I asked them to prove to me that they communicated the XX/XX/XXXX date to me in the loan agreement. They sent me the attached welcome letter and loan agreement, neither of which show the XX/XX/XXXX date. They argued to me that the loan agreement specifies that there is a 18 month promo period and that the loan started on XX/XX/XXXX ; and that the loan maturity date was XX/XX/XXXX, so I should have known that XX/XX/XXXX was the date by which the loan needed to be paid off. It seems like they are taking advantage of people by not explicitly mentioning this date so that people miss it and have to pay the interest. They made it more confusing in the welcome call by clearly telling me that XX/XX/XXXX was my first payment date but not specifying when the promo period ends and when we start accruing interest, which I came to find out is a month before that first payment date. Further, their monthly statements did not say anything about this upcoming interest charge until it was too late. See the attached examples from XXXX and XX/XX/XXXX. This process is clearly designed to trap people into paying interest. After they failed to provide proof that they informed me of the XXXX date in writing, I asked them for the recording of the welcome call to prove they told me verbally. They would not share the recording of the call. They told me there was nothing they could do about it and they sent an email to another department that they would not specify. On XX/XX/XXXX, I got a call from a case manager who gave me the same story and apparently could not help me. She did walk me through the welcome call process and confirmed for me that the XXXX date would not have been shared. She suggested I call loan servicing, which I did on XX/XX/XXXX, and they gave me the same answer and would not help me and referred me back to case managers. So I am now going in circles with them and they refuse to put me in touch with or tell me who has authority to actually hear my complain and make changes if they decide it is appropriate. I have paid off my original loan amount ( the {$9800.00} ) on XX/XX/XXXX but have not paid the interest charges I am contesting. In summary, my complaint is that they intentionally did not inform me of the XX/XX/XXXX date, hoping I would miss it and pay interest, but are hiding behind fine print and the expectation that I do math in my head to say that I was actually informed. This is a predatory lending practice designed to dupe people.