My money went down the drain, bad service

My name is Nomthandazo i took out a finance car with westbank december 2016 than december 2017 unfortunately the company i was working for closed down i than called call centre in march 2018 to explain my situation the agent i spoke to came up with what i thought would be a solution, she than told me i can pay half of my installment initially my instalment was 2400 she than told me i can pay 1400 for 3months in the meantime while im looking for a job now this was from april 2018 till june. Fortunately i did get a job in june i than called the call centre again spoke to a coloured guy though i dont remember his name and never took the reference number for that call, i told him since i was now working wesbank can debit from my acc on the 1st of each and every month we did everything over the phone unfortunately no written document to confirm any changes or whatsoever in july i than realised they did not debit, i took the initiation and went to deposit at the bank till now im still doing that, i have sent emails to service but no service at all. To my suprise last month feb 2019 i got a letter from the attorneys saying i owe wesbank 15000 i told them i have been paying every month. Asked for,my,statement there is no month that i did not pay now suddenly im being told that my account is with legal department,of which i have to pay them legal fees and on top of that pay a huge amount of money that is 8000 for 4 months apparently to settle,my account or else handover my car,i am currently unemployed since last year september but regardless of my current employment status i made sure that i paid my instalment every month. Now tell me if this is fair the agent that i spoke to didnot disclosw everything because after 3months of paying 1400 he ddnt advice that my instalment will now change,to 2700 i have been,paying 2400 but still i dont understand how am i owing 15000? Plus i must still pay for legal fees im not working its not fair. The money i have been paying where did it go down the drain?