MFC Fails to debit my account the they send me a letter of demand

I have just received a letter of demand from MFC for my vehicle finance ***.

MFC did not debit my account now they are sending a letters of demand. I have never paid my account in cash or EFT since it's inception in February 2018.

Now MFC's failure to debit my account is likely to affect my credit score and it is actually not my fault that MFC did not debit me. They have always debited and my accounts had fund and it still has funds for MFC to run their debit order.

I find the letter of demand unacceptable!