Unauthorised debit order

I emailed tracker on the 10th of March to query a debit order. I requested them to send me the invoices to query these amount. They did not respond to date. I tried calling their null and void customer services line, after 30 minutes of hanging on the line, the call cuts and you have to wait another 30 minutes. I have been their loyal customer for years. Only way to get to them is to call the emergency line, which they forced to answer you and then they try and direct you to customer services and it cuts off again. I sent them another email today requesting the same info as this month the debit is a different excessive value. These values were not in line with contractual agreement. So I am going to reverse the debit orders today, then maybe they will contact me. There website and app continually logs me out. Absolute disappointment.