Pathetic Service from Old Mutual Money Account

Absolutely disgusted by the service received by OldMutual Money Account, Firstly They closed my query without providing feedback, Not once could someone make an effort to contact me regarding the query, Even Helpdesk division themselves have advised never have they seen this before but here I sit with my money being taken, my credit record being compromised and the phone keeps being cut in my ear! Old Mutual kept allowing funds and transactions to continue running from my bank account and then all of a sudden I have my account in a negative balance. When asked how they could allow transactions etc to be processed I'm told never have they seen a query like this and to query it with merchants?? Excuse me am I banking with those Merchants? I Mean who will take responsibility for this and my affected credit record?? As soon as my salary came in they debited the negative balance instead of having not allowed those transactions in the first place. I just want to close my account and stop all interactions this is blatant disregard of their consumers and I'm sick of it!