insurance flaw

i was retrenched and faxed all my details in, ( twice ) and African bank stopped deducting money from my bank account without consulting with me, or me signing any form of documentation, few months later African bank suddenly deducted a couple months installments at one take, without notifying me of what was going on, African bank threw my account so far back into arrears and just said its because I did not pay, after I explained about the retrenchment and insurance and faxes I sent in, African bank said that my retrenchment was never granted and the insurance department never paid out due to that reason, but African bank stopped my debit orders and lost my retrenchment forms, now its my problem that my account is in arrears .