Question

A mattress company offers a deal where you can buy the mattress, sleep on it for up to 100 days, and then if you don’t want it for any reason, you get your money back.
If I know that I won’t actually buy it in the end—for example, I don’t have the money, and I’m borrowing the money from a friend for 100 days and will have to repay it—so there is almost no chance that I’ll really keep it in the end, is it permitted for me to take the mattress for those 100 days?
 
Maybe in practice they don’t check this, because they can’t, and they probably hope that the experience will be so good that, generally speaking, people will end up keeping the mattress.
 
Thank you very much!