First off, you would need to get the rental towed back to the original renting location. Unless you opted for the rental company's roadside assistance option (which usually is an optional service for an extra charge) then the rental company will charge you for this. If you have AAA or other similar roadside assistance service, then it's highly recommended that you take advantage of that to avoid the towing charge since it's very possible that your credit card and/or personal auto insurance will not cover the tow.

As for getting a replacement rental car, it's generally up to local management’s discretion. Lots of factors go into it—how much damage, whether it was clearly the renter’s fault, whether a claim is filed and active (helping to assure the rental car company they’ll get their money), whether the renter is willing to pay his/her deductible on the spot, etc. Generally though, assuming there was some obvious negligent behavior or unauthorized use (drunk driving or driving on unpaved roads which is against the rental contract), and no insurance/coverage issues, then the rental company should be amenable to doing a vehicle swap on your existing contract.

You may also find this blog post from AutoSlash helpful.