Bayport Financial Services
Random changing of debit order date

I signed a contract with Bayport Financial Services for a loan.
The loan repayment was via debit order on the 25th of each month.
This December they debited my account on the 14th of December when other monies was deposited into my account. This is in contravention with my debit order instruction!
I subsequently instructed my bank to reverse this.
Trying to explain to these on the phone that the 14th is not the agreed date seems futile.

Terrible start to a relationship - ques whose service I will NOT be using in future...