That's a router problem, not a phone problem. The phone connects to the router. From there, it's the router's job to route the internet to the phone. If it's your router, go to the manufacturer's site and look for manuals you can download, or read the manual or CD that came with the router.
If it's not your router you shouldn't be connecting to it, unless it's a public access wifi, like a mall or Starbucks.
BTW, your phone provider (Immix, in this case) has nothing to do with your wifi, which you're probably getting from a phone or cable company.)