Twice in 4 months I have started house insurance c...

Twice in 4 months I have started house insurance cover for it to be cancelled!
Due to direct debit mandate not being returned on time.
This is complete rubbish!! Was sent the day it was received weeks in advance both times.
Staff that rang told me there is ALOT OF PROBLRMS WITH DIRECT DEBIT MANDATES .
So I don't believe the excuse .
Also means I was without house insurance without my knowledge !