Stop my debit order

I paid my lewis account of in September but they still have been taking debuting my account 689100 the store cant stop it they keep asking for bankstatments which I kept on giving to them I sent numerous emails to head office which is being ignored I call them but they say the account is with legal department and they cant help me *** last time I was paying a wrong account seem like I am still paying the wrong account manager at store said he will call me but never did the old lady with my account must retire now very useless