I sent BPO my payslips but 1st class only not registere, and they never answer.

Hi. I recived a Formal Notice from BPO collections, they wants old council tax debt from oct 2004 to jan 2006. I stayed in this property only two months, I thought lanlord ( landlord registered me to CT) will unregister me from CT. I moved to another flat but I do not have any proof of it. Now I recived Notice Of intention to instruct Walker Love. I sent them statute barred letter, should I send them SAR leter or maybe budget plan and ask for monthly payment. My landlord make a mistake when registering me. My first name is TOMASZ but on our agreement and notice from BPO is TOMASKZ. Thanks for help.