I did not know that SilverFox was still in business. That particular design for the D-ring is the worst. The stitching that looks so strong actually perforates the vinyl and creates a tear line. And with nothing inside the vinyl to stop it from stretching it will always tear along that line. We always put a layer of nylon inside and in some cases even metal to insure that the vinyl is only decorative and not taking the weight of the case.
Although they won't fix it the repair shouldn't be too costly. Just make sure that the repair shop adds something extra to strengthen the retainer and relieve the stress.
I highly recommend that it be done something like this,
This is a metal casing that is riveted under the leather on both sides of the D-ring. Then another piece of leather is sewn around it for decoration and extra strength.
Here is what it looks like without the extra leather.
This type of retainer essentially relives all stress from the body.