Where and how to fix my landline in Cairo?

iam frustrated with telecom services, i had many times report my problem and sent my contact and landline number but no respond no call from them or any sollution.
My problem in my line that cause my internet speed downgrade from 2MB to 512KB since 3 months. anyone have any help to find me a sollution? or where i can fix my line real quick? or do you have any contact to someone who really able to fix my line ?

for landline , try to call 111

I can just say from my own general experience that the best way usually is to go to a branch in person.