Old Mutual cannot provide tax certificate

I have been trying since the 25th of September to obtain a tax certificate on behalf of a client which asked for my assistance after Old Mutual informed him that they cannot find his tax certificate. I have been emailing and emailing,even the complaint center and NOBODY has attended to my inquiry. What should I do to get someone at Old Mutual to assist ? Is Old Mutual Not suppose to keep ALL financial documents of file for at least five years like every other financial company? How they NOT find a tax certificate? This is sadly the second time in three weeks that I had to report Old Mutual due to lack of services.