Wrong details

Good day,<br> <br> I have a contract with Altech Netstar via a motor company. I let the comapy know that my bank account no has changed due to someone who hacked my bank account. Now Altech hand me over to a debt company because I neglet my account after I already spoke to them. I request a new debit order form several times to give them my new bank details and they want to take it over the phone. There is no way I give bank details over the phone. I did everything from my side to fix the problem and they kept phoning and threatening me about my account. I don't know what to do anymore just to sort this out.