Home loan poor service and change interest when it's not supposed to change ?

ABSA home loan increased interest which the repo rate has not even changed for them to rectify there mistake they want me to continue paying higher installment until whenever they fix it or I will fall into arrears I mean how long can that be and the worst part it their staff don't seem to help much, I have home loan with other banks but nothing of sort has occurred, I regret ever working with ABSA