Lying and sub par service

Lying. I reported a fault on my line through my isp. Telkom is my line provider. Almost weekly Telkom has to put my line speed back to what i pay for. This time when they called back the line speed was worse then when i complained the first time. Reported it again and this time I was told that the line is syncing correctly. But 3 days prior it was already beter before complaining. Now the telkom employee told me I have to combine the upload and the download speed to get the total speed. I knew he was lying and told him: That is not how it works bull****! After I apologise for my foul language he told me :" Yes it is fine." Hung up the phone. Yes the word bs shouldn't have been said but he should not lie to me. Plus months and months of giving me sub par performance has taken its toll. This person is lucky I didn't get his name or I would at least try and write a formally complain.