Shocking service!!! Very disappointed customer!!!

I bought a lounge suite from JD group 18 months ago. On delivery I complained as all the arm-rests were sunken in. On first sitting the seat tore on the seam. I went into the shop to file an official complaint. I received a phone call from 'head-office' that they have received my complaint. However, to date, nothing has come of this. I am paying this purchase off with them and therefore the lounge suite is still under warranty/guarantee. I have been paying monthly via debit order for this product. The JD group takes their payment as they please. The date for my debit order is the 27th of each month. They take it off randomly as they feel. In fact my debit order went off on 26/11/2015 and SURPRISE again today 12/12/2015. I will NEVER buy from this supplier ever again and will advise everyone I know NEVER to support this supplier unless something is done about this immediately! I am beyond furious!! It is the festive season and they have taken an extra payment with out consent or notice. As a VALUED customer I expect to receive the best service. I have been doing my part and paying for this product... when will I receive MY VALUED SERVICE as promised on the day of purchase?