Tax certificate delay

Absolutely horrifying turn around on tax certificate issue. I contacted Momentum on 04/07/2019 to request my tax certificates for the 2018/2019 period, only when they sent it to me there was no claim showing, I advised them of this and the Awesome lady I was talking to tried to redo the document and resend it only to have the same issue brought forward, she logged a query/complaint/whatever for me with reference number ********** 97, stating it shouldn't be more than about 3 working days, I called back on Tuesday 09/07/2019 with the issue still not resolved, I gave them some time and called back on Thursday 11/12/2019 with again no resolve, I asked to talk to a manager to be advised they went into a meeting, I was advised the manager will call me back, up until 10:34 on 12/07/2019 I still had no call. Please resolve this issue today on the latest or I will start taking this further.