Guarantee to get a degree? Are you kidding? If you want to buy a piece of parchment, there are garbage institutions out there that will sell you one. If you want a piece of parchment that means something, you’ve got to prove you can do the work, know the material. No one wants to hire an engineer or surgeon who partied their way through X years, but got to graduate solely on the basis of having paid thousands of dollars.
You don’t pay for a degree, you pay for the opportunity to earn one.