Unnecessary Call Out Fee Unjustified

Many technicians have come to my house over a period of two years or so. Each time there has been a problem with the line, which is ridiculous. How can Telkom not make sure that the same problems do not recur for three years? Today I received a statement saying I have been charged an unnecessary call out fee for the last visit by a Telkom technician. When they came out, they first said my modem had a problem but when I told them this was not true, they suddenly found a problem with the line. And now suddenly I am told, weeks later, in an e-mailed statement that I will be charged a call out fee because there was a problem with the line. What is the justification for this? Why was nothing said by the technician on the day? Why when I phone Telkom does no one ever answer? Why do I have to log a call, with the automatic result that a technician comes out? Why did no one phone me to ask questions before sending a technician out. Please reverse this charge.