fax number for Federal Bond Collection Service F.S.

I have 'in vain' attempted to fax a pre-payment letter requiring them to accept my 'negotiated' payment ($35.00) as the settled amount to clear this debt from the bureau's.

The number I called (also on their website) is (215) 288-9101. Each time I send the fax (over 10 times now), I get a message from the printout saying that the line is busy. However, when I dial the fax number on my phone, I get the normal 'pinging' sound that occurs between fax machines in communication mode.

Can someone tell me what is going on and a 'real' fax number for this company. I emailed the recruiter at this company and asked him to forward my document to the rep (Darryl Holman) but received no reply.

Thanks,

Rudy