Phone router not working

I recently had a phone added to my account. A technician changed out my old router with a router that allows me to use a phone. At first all was fine. The technician even stated the the new router was faster. The next day i lost my internet connection. I even disconnected my wireless router hooking the phone router directly to my computer. All i got was a limited connection which actually did nothing for me. After many attempts of rebooting and so on, i finally hooked the old router back to my computer getting connected back to the net. Has anyone experienced this issue?