If you're referring to your speed dropping when you run out of data, there's nothing to fix. This is normal. The plan size is chosen and agreed upon during the sales call. When you exhaust your plan's monthly allotment of high speed data you are subject to the Fair Access Policy, which means your speed "may be reduced to as low as or lower than 1 Mbps."
If you feel you were misled during the sales call and it's been no more than around three months since that call, you can request a sales call review. Depending on what's found in that review, you may have recourse. The reviews can take up to a week to perform. You can request a sales call review in the "myAccount and Billing" section.
If you simply want to cancel the service, you can do so by calling 866-347-3292. Please keep in mind that there is an Early Termination Fee when cancelling the service during the 24 month commitment, with that ETF being $400 for the first 90 days after activation and $15 less per month thereafter.
Good morning 9372,
It's been a while since we last heard from you, so we will close this thread. Hopefully Gabe's suggestions helped. If you still have concerns, please start a new thread and include a detailed explanation so we can better assist you.