Congrats on getting your MTC granted! I would go back and read cheeses first post particularly under the "filing the arbitration claim". Now that you have a court order to go to arb, you can proceed as advised. Here are some highlights I copied from cheese: "Remember that when you ask for arbitration and file it, you have now flipped the roles. YOU are the "Claimant" and THEY are the "respondent". This is essentially like you are now "suing" the JDB, only in arbitration instead of court. Think of it just like that. You would not file a lawsuit against yourself, so do not do it in arbitration. I would never mention THEIR claims against me, nor the debt in any way."
Once the MTC is granted they MUST either pay the deposit to proceed with arb or ask for a settlement (hopefully mutual dismissal). The court should put the case they filed against you on hold until a certain date pending arbitration.
In my case which was also syncrony/walmart, once the MTC was granted I filed the arb case about 2 weeks later. The opposing law firm never responded to anything from JAMS. They waited until the last minute, literally, to offer a mutual dismissal settlement. So don't be surprised if you don't hear anything until the deadline approaches. File the case with with the arb company and stay on top of anything they ask for then do as cheese advises in this post.