Unacceptable response

The executor of an estate is trying to get the CGT certificates for a deceased estate to wrap up the tax affairs. Old Mutual PLC shares were sold out of Estate. We are getting the run around - calls being dropped, security answering and being told nobody is in office,...including being told by Link Investor services who sold the OM shares - that they do not have to provide. This is UNACCEPTABLE. How professional is Old Mutual?