Very bad and disappointing service from so called standard bank

Hello my name is Oupa Mathikga id no *** contact number *** i am pensioner residing in soweto .I had a house bond with standard bank together with house insurance paying regularly for more than 10yrs . On the 28th December 2021 i pay my last installment which it was R16200.00 i also have the receipt with me and i asked them to close the insurance but first they my provide me with the tittle deed and we agree on that but to my surprise standard bank came back and said i owe them R1500 for insurance even though i wrote a letter to them to close the insurance and now they dont want to give me my tittle deed saying that im owing them which means every month they are adding interest on my account .Im so very dissapointed on them cause i was their client and i paid them fully according to my knowledge.Hellopeter please help me sort out this problem that is eating me everyday and it will take me to an early grave as im old and not working