Home Choice ********** and putting up a legal face

I bought a blanket telephonically with home choice, we agreed on the monthly debit order they debited twice correctly, then they skip debit orders to increase interest on your account. they will debit in one month and skip the next month and keep their sequence. They are currently calling me and putting words in my mouth. I enquired about settlement the amount was higher than the actual price, when six (6) debit orders have gone through to them to cover the actual price.