Unacceptable Treatment From Lewis Stores

Since opening my account I been paying R1500. My installment is R1163.47. According to Lewis I am in Arrears I phoned on 14th December I was told that in 3days someone will give me a call. It's now a week + and no one has called my statement for January and I am in Arrears. How can someone who has. Been paying via Debit Order be in arrears. This is outrageous treatment from Lewis and this not a first incident I am experiencing with Lewis UN