One's attitude dictates everything.
I think taking below investigative steps will help the DSL provider, whoever it is, to sort out the problem effectively. Complaining alone does not help.
1. Are you using regular Bell landline local-phone service? If not, you need to inform your DSL provider that you need the dry-loop DSL instead of the regular DSL.
2. Is your regular phone line working well? i.e. Can you make regular phone call successfully? This will ensure the phone line that carries the DSL signal can reach your modem. You need to use the same phone jack/socket as the DSL modem/router to make the phone call, in order to verify this. You may need the DSL-phone filter to make the phone call.
3. What type of modem (or modem-router) are you receiving from the DSL provider? Read the user manual and ensure you connected all the required cables properly: power-supply/phone-line/Enternet cable.
4. Has the modem/modem-router already being configured properly? Or do you need to configure it yourself? The DSL provider should have sent you such information. Depending on each household's situation, the modem-router can be configured as modem-alone (bridge mode) or modem-router, in which case you need to specify the protocol (such as PPPoE or PPPoA), as well as the VPI/VCI (such as 0.35), some DSL provider also needs you to specify the MTU (such as 1492). There's also choice of whether to enable/disbale DHCP server/client, depending on your choice of dynamic IP or static IP service you get from the DSL provider.
5. Verify the modem-router is working fine after turning on the power. The LED-light monitoring DSL signal over phone line should be on (and steadily on).
6. After that, you need to either use a PC or a router to connect to the "Ethernet" port of the modem to verify the connection to DSL provider is up and running.
7. Use web browser to check the speed of your internet connection using
Speedtest.net - The Global Broadband Speed Test
Anyway, a lot of work before you can enjoy a good internet service. If you are not good at doing all these, either seek help from friends, or choose a DSL provider with good/strong customer service, such as Teksavvy. Always search the internet for comments/feedbacks from previous users of the DSL provider you intend to use, you will know what each of them is good at or bad at.