Unfair treatment

I requested for a cancelation in March for my funeral policy,but sadly it was not canceled April I called them requesting a cancelation letter they said they processed my cancelation on the 7th of April and the debi check for my premium has already been sent through, on the 15th they debited the premium then I called to inquire the explanation that I got was I need a 30 days notice to cancel my policy. 12 May I call the requesting can letter they tell me they'll email it but will still debit the premium I've been loyal to clientele I never claimed even once, I never received any cash back from them since 2015. I feel it's really unfair what they doing hence I want hello Peter to intervene