Why can’t I cancel an online success strategy course?

Generally, you need to be very careful when signing a contract. If you are told there is a right to cancel, ask to see it in the contract. In Illinois, there is a three-day right of rescission if an installment agreement offer is solicited (a door-to-door sale) and there are rights of rescission for a couple specific types of contracts, but generally contracts are binding. Here, there may be some arguments an attorney could try on your behalf, but there is no doubt that an attorney would look to be paid hourly to defend collection of your obligation. With a company like you describe, another question would be whether the attorney general's office would take a look at their conduct (perhaps there are already similar reports) or whether there would be some basis for a class-action attorney to think that enough people have been hurt by improper tactics or a scam.