absa unauthorised deduction

i currently struggle to pay my debts, and agreed with absa to make an payment arrangement to pay R500pm, on my credit card, it was going smooth, and i was paying it monthly, after making an arrangement, in side the bank. now i got a refund from my taxation, and the money was in my account, and i was planning to pay the part on my hospitilisation, since i was recently admitted because of ill health, that was an unplanned emergency. now i dont have this money to pay my hospital account, i am going out off my mind because i now no longer feel safe to bank with absa, as they are not professional to ***** the money out of my account, after i did arrangements. i am utterly disgusted, i never thought this can happen to me, its totally not acceptable....!