Not informed of debit

I have a credit with ABSA that I couldn't make payments on since last year June as I was unemployed. I recently found and a job and on the 25th made a payment on the account, was surprised when an amount of R4000.00 was debited from my savings but was not even informed of this nor asked what payments I could afford. How am I even supposed to get through the work with transport money as I use public transport which is quite expensive. How will I make it work to be able to make those repayments when I've been debited such a hefty amount????