Delayed emails and rude, unhelpful call centre

I am extremely frustrated at the poor service we have received from Telkom. We have had delayed emails since the beginning of 2015 which has not been resolved to date. Emails only come in 30 minutes - 3 hours after they have been sent. When I called on 28 October 2015 to follow up on the problem, I spoke to 3 different consultants and after asking me to hold on they just hung up. That was so rude and such a waste of my time that I gave up for the day. I have just called back today 30 October 2015, was transferred once and after being told that he is still on the line and I must just hold on, he hung up on me. I then tried to report this fault online and it says that I can't because a fault has already been reported?? This is impossible as I haven't even spoken to the consultant for more than a minute, just answering security questions, before they hang up on me. Please get hold of me for a change or just fix the problem with our emails as it is a service we are paying for and this long delay in receiving emails of sometimes up to 3 hours is affecting our business! This is UNACCEPTABLE SERVICE. This problem needs to be rectified URGENTLY.