IPS PROCESSING UNATHORISED DEBIT ORDERS - ********!

IPS contacted to sell me their product. They advised that I can use their products for a month as a trial run with no charge, to see if its something that I could be interested in. They delivered a large supply of their products. After 1 week of using their products, I called to advise that I will no longer be taking this on and that they should come collect their products. They requested that I at least use the products until the end of the month, of which I respectfully declined as I cannot afford the monthly payments, they offered me a discount and i refused that too, still requesting them to come collect their products. I was advised that this will happen, they then went on to debit my account of which I managed to reverse. A whole year has gone by and they have not collected their products nor debited my accounts. Out of nowhere they debited my account on the 1st of November. I called the bank to reverse this debit order and cancel it as it is not mandated. The bank advised that IPS had given an instruction for the debit order to be non-reversible. This is absolutely ridiculous and I cannot be bul**** into paying something I did not agree on. The worst part is that they don't get back to you nor pick the phone.