Terrible service

I have sent a complaint last week . To this day no one has attempted to call or email me regarding the fact that I am not being debited now for the 2nd time , regarding my personal loan. Now , I am in arrears and have to make arrangements as per my app ...and made to look like I don't see to my commitments when the money was there to be debited yet nothing happened . But interest is just racking up . How does that work ??? Someone better email me immediately about this , as I am often not available by phone .. I want this sorted out ! Or I'm taking this matter further .