3 weeks waiting for Black Box Installation

We have been waiting for 3 weeks now for SADV to come and install the "black box". We already have fibre (small white box) in our home, all we need is that black box. They said you will be contacted to set up appointment and I'm still waiting. If i phone them, very friendly people awnser but they all say the same thing.. " we have escalated to our technical manager you will receive a call" My request as been emailed/escalated several times as per my calls with them I understand the the use of external contractors and they have a lot of work but really?? We in a situation were SADV is the ONLY Option we have and 3 weeks waiting for a small black box to be installed is concerning. Would really appreciate it if someone, anyone can just help me please.