This is a typical first responder.
Response is probably required its called brief in response to opponent's response. In the reply brief one can attach exhibits such as initiation /filings, card agreement etc. It may also be wise to use case laws in support of .
Check RCP for response time to motions such as this. Reply brief usually has a short timeline like 9-14 depending on the state court rules and guidelines should be followed like any other motion filed in court. (filed, stamped send opponent a copy CMRR, etc).
In support it is a good idea to reference to case laws where arbitration in a written contract is unavoidable, irrevocable and binding in its terms and per FAA section 1-16 , Att vs Concepcions et al.(SCOTUS), Moses cone vs Mercury hospital (SCOTUS), etc. there are many useful cases to search.
What state ?
JDB or OC?
Does your court require motions to be scheduled & heard ?