Worst Service Ever

I have had a temporary loss of income. I sent them an email to make paying arrangements. They acknowledged my paying arrangements and told me there will of course be 10% penalties which is fine. After the arrangement they still try and deduct money from my account and even change the amounts of the debit orders to see if they can get any money from my account. This month 3 debit orders tried to be taken off my account after I have explicitly told them I have a loss of income and made a payment arrangement. Any bit of money that might come into my account is for family helping me with food etc. They take up to a week to respond to your emails (if lucky) and the consultants who call you all tell you the same thing with so solution. This is possibly the worst service I have experienced and now forced to take the legal route.