Settlement Discount Dispute

last month on the 15th of August, African Bank gave me a Discount Settlement Letter to pay off my Loan with them. its was Valid for two months, until the 15th of October. i then on the 20th of September 2019 went inside the African Bank Branch in Pavillion. where their consultant told me the balance is R7501. and i said but the Settlement Discount letter i have says i must pay R3000 rands, which is what i paid on the 20th. i will not pay them any amount not a cent more, not when i have a Discount Settlement letter stating cleary i have to pay them R3000 to settle and close off my loan with them. and i need the paid up letter ASAP and also they need to go and clear Credit profle and remove themselves. this is not the way to treat clients African Bank, especially not knowing the secrifises we go through, to settle your accounts while other poeple are ignoring your calls and running away.