FNB life never runs my debit orders

On the 17th Jan I sent an email to life that I want to amend mu banking details, they responded back saying everything was amended. On the 26th and 27th the funeral and life cover never deducted when I called and asked them they told me it never run so my cover has lapsed. Who fault is it it never run its fnb because I sent an email and they responded back even saying they debit double why is it that it didn’t run don’t know even sent them countless messages never got response back. Can you assist because they saying they cannot reinstate it