After many months. I keep receiving text messages ...

After many months. I keep receiving text messages from this company saying I owe money. I have told them I do not pay bills over the phone. I have asked for a copy of the bill to be sent to my address. I have still not (after 4 attempts) received the account. Very poor customer service. And I was also threatened to pay the account... that I haven't EVER seen!
I cannot help if they are unable to follow instructions. I guess this saga will continue.