Sudden 25% Installment increase without notification

I have had a home loan account with Standard bank since 2012 and during that time i have never had any other communication regarding installment changes not even in my statements which have been recently emailed to me. I have had numerous communication since then with standard bank regarding changes i required due to change in employment and change of surname.

In the latest statement (statement No. 12) issued on the 28 02 2018 there was no indication in the statement of any changes to the installment nor any increase notification was highlighted, furthermore i have been paying slightly higher than the stipulated installment starting from 2015 November which is apparently not appearing on their system but is reflecting on statements sent to me. I would like all implications such as interest levied on my account which unfolded from this error from standard bank's side to be reversed/waived as this was not my doing had the changes which were meant to have occurred on the account have been effected when they were supposed to have this would not be happening.

The sudden change in installment of 26% is just ridiculous and unrealistic to expect a client to suddenly pay without prior notification. I also do not appreciate the *****ing of my credit record by issues such as these which are a result of an error which the bank made. I have received communication that i did not pay my installment and my account sent to credit recovery even though i paid my monthly installment as i have always done, just to find out standard bank has decided unilaterally to make adjustments to my account/ installment without prior engagements with me as their client. This now comes across as if i am a risk as i do not honour my installments as per credit agreement.