Multiple requests for tax certificate ignored

Good day - My father died on 31 July 2015. I was subsequently informed by Bestmed that I (as the agent to the Executor of the estate) would only be able to obtain a tax certificate for him for the 2016 financial year, four months after the date of his death. Consequently, I have been trying since 30 November 2015 to obtain the tax return which I desperately need so that I may complete his tax return before I move to a different province, ultimately so that I may comply with the Master of the High Court's directive of submitting a liquidation & distribution account by mid-February 2016. I e-mailed [Email Removed] on 17 Dec, 21 Dec and 5 January (Ticket number E85BFD155B305). Yours is now the only certificate outstanding. Is there someway that I could have the process expedited please? Or at least receive the courtesy of a response? Thank you.