incorrect debit date

My contractual agreement with Indwe Risk Service was for the debit for my car and home insurance to go off on the 1st of each month, however they have been debiting one either the 30th or 31st which is unacceptable because sometimes the debit is declined which then creates a bad credit history for me, I called and emaemailed the first time it happened and the matter was resolved, however they have done the same thing again, this has to stop, it is really an unnecessary inconvenience on my part, can someone from Indwe explain to me who or what changed the initial agreement? This is getting out of hand and I am really tired of having to write emails and make calls <br>