Monthly installment increases every quarterly for home loan bond

I took a home loan with SA Home loan in 2019. 1st payment went off end of Oct 2019. Lost my job same year in Sept. I did notify them. However, I kept my debit order running.

2020 Nov / Dec I requested for my payment to be reduced for 4 months. They allowed 3 months. 2021,i asked them to extend my 20 years contract due to my financial issues so my monthly installment can be less than what I have been paying. My request was declined. Nov / Dec, 2021 I requested for another payment plan to pay less for 4 months but only 3 months were given. I managed to pay only for two months thou.

2022 April, I did arrangement with one of their employees to pay R 4500 pm instead of R 4400 that I was paying. My debit order date is 3rd of every month. June debit order was returned due to insufficient funds. When I asked Tatum Lynette at SA Home she told me debit order was for R 4600 due to quarterly increase. I was not made aware of this, as I believe if there is an increase, letter has to be sent to client. She forwarded me a statement reflect monthly installment of R 4600, same statement states that next increase will be in Aug 2022,how do we do quarterly increase? How possible is that?

I informed SA that am still not working, been trying to rent my place out now they come with quarterly increase! Is this how people are losing their houses, is this how they want us to sell our houses because obviously they will benefit and I will lose... Honesty, i am so disappointed