POOR COMMUNICATION

a gentleman came over to my work place 3 years ago, he said he was a represantative of DMC, relating to my standard bank account, he made me sign some documents which were acknoledgement of debt. suprisingly im receiving calls about non payment of this account. DMC is not listed and i have been trying to get their contacts without any success.they are debiting my account every month but i also get calls about non payment every month.