Pay date changed but loan recalculated to add extra interest monthly and term extended by a month. Now go recalculate this loan in my benefit so that it can be paid off in 24 Months

Good day,

I took out a loan and my pay date changed from 25th to month end. I Informed the bank and they recalculated my loan and extended my loan period. But every month since I've requested the change I'm told that my account is in arrears and that my insurance was not paid and interest is immediately added. They do a Debi check, so why was my loan recalculated and a month added and my outstanding balance increased if there is no benefit? I could have just not call amd be done with my loan in 24 months like agreed but I am against what they did as well as the fact that they never cl me back as the branch staff cannot assist.