Complain

I purchased a DTSV decoder with installation on the 04/04/2019 till to this day no installation was done , i was given a number ********** 567 to contact the agent to install the dish but i got no response from that number just rings no answer . i went to the store days later and i escorted to the multi-choice agency and i was told agents are busy i should continue calling the number. However my mother bought the same DTSV decoder with installation from another store and installation was done on the same days. Please tell how is it that another store can get agents to work quickly and the Pep store in Pan Alexandra cant get agents and we are not even told on the day of the purchase that it may take long for the installation.