Premature billing of my account

A premature debit was done on my account without my permission causing me to incurs bank charges u cannot afford. I have contacted the centre updating my cell number and reminding them of my pay date. They are alleging that they've sent me an SMS prior to the debit which I have not received on either number which is regularly checked. Neither have I received a phone call confirming receipt there of. I find this completely unacceptable as the same occurred last year and they are now not willing to take any responsibility there of. I've been loyal to my payments every month. Never missed one payment or delayed it.I feel that Capfin as a company should take respsonsibilty as 1: I have contacted the call centre changing my primary number, and 2: I have infmd of my pay date.