If it's jammed when powered off then it's likely to be a stripped gear which you can replace yourself. If it's anything more than that such as a burnt out motor then it's fit for the trash unless you want to save the case/gears for spares to service others of the same type you may have. Most of the reason why Savox only deal with warranty repairs is that it isn't economically viable to repair a servo if it is more than gears or a case which are both user replaceable.

Servo failures suck and I don't personally get much more than a seasons racing out of a pair of servos especially in a heavy nitro buggy but yours has had a good run if it's a couple years old so I'd be just replacing the complete servo.

If you want to stick with Savox whose support in warranty is fine you could try the newer 1271 for a coreless motor unit or the 2270 for a brushless motor version. Brushless should, in theory, last longer than coreless. If you want a change then I'd highly recommend the Sanwa ERS-962 which is a HV capable servo and is also waterproof. Either of the above will do you well.

As in many things in technology the trend nowadays is to make a product which isn't really designed to last forever nor is it very repairable. Look at computers and TV's etc gone are the days of modular units which could be repaired. Now if your tv packs up its time for a new one. Same with RC electronics these days. Even if your servo packed up in warranty and you returned it 99% you'll receive an exchange item back your original servo will probably be thrown out.