Cannot login on our emails via our computers

During the last four weeks we cannot log into our emails via our computers. The first time this happened, it were 3 emails on 3 pc's in two different areas that was affected. At first Vodacom kept telling me it's my pc, but eventually I got through to somebody with savvy. He tried to login on his own email via the route I used and found he couldn't do it either. Vodacom repaired the one route, but 2 days later we experienced the same problem. Again it was fixed, but it keep recurring every other day and every time I have to phone. It is now 2 days again and I really need to send emails from my pc as it is documents which I have to download, complete and resend. When I phone Vodacom, I have to hold on for average of 4 minutes before somebody answers me and then they keep cutting me off. PLEASE Vodacom, fix our emails so that we don't experience the same problem every second day, it is frustrating!!! Your service suck!!!!!!