BANKING DETAIL CHANGES

I called the call centre yesterday,to ask for a bank statement,i was asked when did i do my last payment,and told i do it every month as usual,i was then told by a consultant (Nomandels) that there bank details have changed,the same one i have been using for more than a year and should go to the bank for a statement so she can following up,this is not my error,as i was never informed of any changes and do not have the time to go to the bank for an error on there side.