The Cash Line its a scam, Internet

I took a loan of 450 dollars  five months ago.I thought it was like a loan that it charges you like 300 dollars more with interest, and it happens that i call five months later and i owe them a thousand dollars and they tell me that those are interest and fees. the person was really rude and tells me that is my fault.

i told them whats the problem, and they told me that  every month it was 300 dollars because its supposed to be paid in one payments. they told me if i read the contract, they never sent me one or warned me at all. today i payed i payed it all. this is scam, if not then what? of course they have my check account of course its easy to steal without responsibilities. for others beware of this scams that offer quick and easy money.