Product: Payday loan

I recently took out a payday loan from Big Picture Loans online, and I requested to borrow {$600.00}. I was quickly approved for the money, funds transferred to my checking account on XXXX/XXXX/XXXX and things were set for me to begin repaying two weeks later, on XXXX/XXXX/XXXX. I had understood that there would be a {$210.00} finance charge in addition to the loan amount ( bringing total owed to {$810.00} ) which is quite steep I realized but I was in a desperate pinch, and figured it was the penalty I had to pay for mediocre credit and a quick loan. After receiving an email stating that the entire amount of the loan would be deducted from my account the next day, I called Big Picture Loans in a panic, as I did not have the whole {$600.00} and did not expect that it was due in one sum, immediately. After the woman on the phone explained my option of pay everything immediately or pay the finance charge only ( {$210.00} ) and be charged another fee for breaking up the payments, I most reluctantly agreed to suffering another one time fee of {$210.00}. Now bringing my total due to {$1000.00}! At this point I was frustrated, confused, and very upset as I felt like the company had me over a barrel and had not explained to me or provided any written terms for all of their hidden fees and now I was stuck taking on more debt. 
Since my first payment on XXXX XXXX XXXX, I have paid on time thru automatic deductions from my checking account at {$210.00} intervals every two weeks ( total so far {$840.00} ) As of next week, I am scheduled to have the last {$210.00} withdrawn from my account with my total paid out to Big Picture Loans of {$1000.00}! 
Upon looking at my account information this evening in anticipation of my loan being paid off I was horrified and bewildered to see that Big Picture Loans has me slated for 20 additional payments after what I thought was the pay off amount on XXXX XXXX. My APR is 967.555 %! My pay off calculator indicates I will be done paying for the {$600.00} I borrowed at the end of XXXX XXXX and my total paid to them will be {$3600.00}! 
I am utterly flumoxed by what these fees and payments they have scheduled are for. I have never been made aware of this exorbitantly outrageous APR, was never communicated with as far as any debt owed to this business beyond the original loan amount, the finance charge, and the additional {$210.00} charge which even still was for vague reasoning that I did not at the time think to pursue. Never did anyone on the phone indicate or even mention that I would be in a situation where I would be paying {$3600.00} over the course of a year for {$600.00} borrowed. Not once was a number of payments mentioned, and not once was it discussed how their finance charges can be accrued. In all of my emails and even my account summaries ( which I am happy to attach or forward somehow ) the wording for finance charge is loose and vague. Things like " pay off your loan quicker and avoid finance charges '' but upon looking at my account 's scheduled payments for the next year, there is absolutely nothing delineating what is considered a fee and what is considered the principal loan amount. I genuinely have no idea how to " pay off my loan quicker '' ... .I thought I just did. 
**please see attached digital files, first is a screen shot of my current log into my account, note it says in plain text : To Pay In Full Loan Amount {$600.00}, Finance Charge XXXX XXXX Pay off Balance $ XXXX I am not proud of it, but I have used pay day loans in the past and have never had an experience like this. I am frightened at the prospect of paying these people for the next year and jeopardizing my credit and personal finances.