Very bad afterservice

We have installed a Neotel line. Since the very first day we had a very weak signal (the technician that installed the line said it was because it was raining, and it will be fine as soon as it stop raining) (he installed the line in our kitchen and not in the office as this was the best signal). But still we had a very bad signal (line is scratchy and calls are dropped). I have phoned a couple of times, and was told that they will send somebody to have a look, but nobody came out. Then I started sending e-mails and telling them to fetch the phone, as I cannot use it. On the 19th July 17, they send a company out namely SS Telecoms to have a look. On the report the service technician states that the incoming and outgoing signals is very bad, and he suggested an antenna. Ever since I have send them 4 e-mails, and nobody has rep**** back to me. I am even prepared to pay for this antenna, I just need a working phone! We are paying them every month for nothing!