This company offered me a product which I returned a week later as I could not use this product

This company offered me a product which I returned a week later as I could not use this product. They sent their courier service who picked the parcel up. Then, they began taking off the installment via debit order, which went on for about 3 months. I went to my bank and disputed these debit orders. I was refunded the past funds by my bank with no fuss. This month, I noticed that they deducted again from my account. Being a pensioner, start the whole process over. The aggravation and funds being deducted for unpaid items can not be compensated for. I hope someone from this company will wake up and solve my problem. When I phone Cell C, (084 145), nobody seems to know anything. This might be the problem why this company always posts losses. They themselves don't know what they're doing. 👎😭