Credit solution from hell and terrible customer service

I really should have known better, went in at one of the Sleepmasters around my home town to laybuy a bed. Long story short I ended up buying it on credit , on the day the monitor on the computer that displays what I am agreeing to when I sign wasn't working so I assumed no harm would be done. A couple of weeks later I receive my statement I am very alarmed by the very high loan amount. I enquire about it because I never even got an invoice for my order let alone an explanation of how much the delivery would be and in the invoice there are insurance things that no one explained anything about to me. I called customer service to request for my invoice, after some back and forth throwing me around someone finally sends it. To my surprise there was an extended warranty on my invoice that I never requested. I try taking it up with customer service they tell me I have to seek help from the shop, after weeks of literally begging I finally receive a letter that says the extended warranty has been removed effective 31st of August. 4th of September I requested a settlement balance because I have had it with the terrible customer service. Settlement balance comes with no changes despite them saying they have removed the extended warranty and me making two payments already. I call customer service again they tell me it looks like nothing has been done on your account, I ask them how can they help me? They send me straight back to the useless shop that hasn't ensured I get assistance in the first place, they never even give me an update without me calling them. It's been two months now fighting the same thing. All I want now is to settle and part ways as this is credit solution from hell.