Unfair deal

I have had a vehicle account with Wesbank from 2016 March 05 and the account was paid through my paymaster at work which was my arrangement that the paymaster deducts the money from salary and pay it to the Wesbank account. This had no issues until the account had the balance of R2700 and some few rands and the payment amount arranged was R9540. I then thought that it would disorganize the paymaster to instruct them to pay the amount due but to pay the whole amount. Now I am being sent from pillar to post when I claim for the difference between the amount owed and the amount paid. They are now saying I must get a proof of payment which I got from my paymaster and sent it to the bank. They are now saying that that proof of payment is not enough to warrant a refund. They say I should get a bank from which the money was paid. Unfortunately, the paymaster cannot provide the receipt as they pay the bank in bulk. I would like you to publish this story so as to embarass the company