what to do whan a case in PA is denied for not providing certfcate of service to a defendent company who left the adress 6 years earlier?

This case is a mechanic lien in PA. After putting the lien against alreday receorded waiver of lien the company did not do anything more. That was 5 years back. Since last year I am trrying to remove the lien of my own. The court papres I sent at the last known address came beck with notation "left without any forwarding address". I asked for a defualult judgement but did not provide any ceretifacte of service thinking that this is uselss since along with my prayer of default judgemnt I attached the entire retuned envelope. The case was denied for failure to provide certificate of serevice. I immdeiately sent another letter to court and defendent saying that I personally visited the site and they are no longer therer . Meanwhile the mail to the defenadant came back again. I did not hear anything form the court and five months passed. What should I do? Thanks.