Terrible treatment by the bank

I've bought a vehicle through Wesbank and was not working for some time. But always tried to pay them back, though it was not according to my monthly installments but I paid. I still pay them,but after 2 months someone will come knocking and saying they are here to colic the vehicle. I don't even owe them more than R20 000, but they are quick to come and collect the vehicle. There are people who owe them tens and hundreds of thousand but they don't torment them,whose these people don't even try to pay the least amount they could. I'm willing to pay them it shows but they treat me like a hooligan who wants to run away with their car. At least they should see good intentions that I really want to pay them. They don't even send me statements or anything,all they know is to rock and say they here to collect the vehicle. I'll pay this vehicle,I bought it so I'll finish it off. At least I'm not running away. Let them give me a chance, I've started a new job this month I'll pay them monthly from now going forward. Worse I have a business account with them to show that I'm not running away, I could have changed banks if I had intention of not paying them.