There are exceptions -- if you use one of the small supposedly-free VPSes it might just work, and at least one person has done it in an Amazon AWS instance (only free for 1 year, but that's probably longer than most "free" providers will last):
I am having the same problem trying to insert a repeater on a paid shared hosting account. Is there no other option for me other than go for another hosting account? I already paid for one full year so I don't want to lose my investment. Thanks!
You're not losing anything -- if it's just a paid shared hosting account you can certainly still use it for what it's intended for -- web hosting. A repeater functionality breaks the terms of many of these hosts anyway. And it's way cheaper than most VPSes.