Verizon outage

I used to have Verizon, and the internet was fine, pretty fast, and I never had laggy Xbox live. One day we had an internet outage and a month after the internet outage was supposedly resolved, Verizon couldn't get ours running again (2 technicians came!). Anyways, we got fed up and switched to Earthlink. Our Earthlink Setup- we have a modem connected by cable in the basement, and our linksys router we bought connects to that. We connect, but the internet on the computer is seemingly quite a bit slower, Xbox Live is super laggy. We knew the connection would be slower, but not this much slower! Should it be this bad? My main concern is Xbox Live, I can deal with slow internet browsing, but Xbox Live is laggy to the point where it is unplayable. Would the router and modem being in the basement have anything to do with it? Can I call in and just request to be given a faster service at a higher fee, of course, and without them having to come in and set up some new thing or whatever? Please help. Thanks in advance :)

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