DEBIT ****

Hi these people have been wrong fully debiting me since i signed up with them i keep on sending them proof of payment then they say my account is ok then when i phone next month they say im in arears for 2months. I want to sue them its going on for 5 months now and still same problem i never evens got my free month that they promised and my reimbur*****t. Please hello peter sort this people out as they told me theres nothing they can do im suffering cause im double paying every month for a product i work with the bureas and i know whats the consequenses if a company debit wrongfully so please help me its been 5 months with this problem