Poor Network and Delivery Service - 5 weeks no results!

I have poor network on my home router and have been waiting for delivery of my voice call SIM for 5 weeks! I have been calling week in and out for the past 5 weeks requesting assistance and i have been given false info from delivery will be done in 3-5 working days, to we will prioritise your query- an agent will call you in 24 hours, and none of this has happened, no email updates no communication from courier company. To make matters worse i work from home and my main router with unlimited data is not working properly, i have also reported this 5 weeks ago and i have been rebooting the router as per request yet i am til this day experiencing the same issue- poor network. This is frustrating as I am working from home with poor network and unable to make calls from a service i am paying for and have been a loyal customer for the passed 6 years!!! Unacceptable!