Altech Netstar
Cannot get through to agent

I have tried to phone Altech Netstar numerous times in the last two days on the 011 207 5000/6 number to change my details and enquire about adding a vehicle. You get through however you are put on hold to speak to an agent. Yesterday I held on the line twice for over 10 minutes at a time. I tried again this afternoon and gave up after 25 minutes of being on hold. This is absolutely unacceptable