Very poor service

I had relatively OK service with Vox even though I've been over billed regularly for the last 2 years(I didn't mind much cause I need the internet connection for work purposes, and I tried to build good relationship with them.. , but ever since I canceled the LTE to change to ADSL(due to unstable connection issues lately and in my complex their is no fiber yet, hence I opt for DSL) now even though I paid in advance for the LTE service while waiting for them to connect my Adsl... I'm having endless connection issues... Is it because I canceled the service, they feel that they no longer need to satisfy my needs.. 2 weeks now I'm waiting for technicians to come reinstall my line, Since they didn't install the line yet or even have the decency to contact me, I now concider another service provider... Since I'm part the complex body Corp and busy negotiating business for them... In our meeting today I informed them about my service issues and that I will try and see how they will resolve it before we as the complex body Corp make use of their services... I'm so disappointed..