Debit Orders that was not collected by the bank

I have a personal loan with Neb bank and for the month of May and June the was no debit order requested in my account i sent email to [Email Removed] to want to know why the was no debit order that was taken for normal installment,i did not receive any answer except they apologies for inconvenience caused and i ended up transferring the money from my account to their account and i was not told that i will be charged penalties for the two months that they failed to debit their installment.i only received an sms on 26/09/2015 regarding arrears added,I called them on the 28/09/2015 to find out and i was told i am responsible for the arrears charged for the two months i asked who'S FAULT is it that they did not debit because the money was there and i have bank statement as proof i was transferred from one consultant to another .