Refund not paid- deducted money bank acc.

When I realised money was deducted from my bank I battled 4 months with their call centre to accept that they have received the correct pages. Then they said due to Dec. I have to wait until end of January for the calculations, then they start postponing the pay date, and ask if they can pay over 4 months, but now they did not even pay the first month. I have never given this company any authorisation to deduct this money from my bank account.