Your booking is essentially identical to ours (Econoflex with many changes, paid with companion voucher, WJ$ and credit card).

As I came to learn you cannot cancel online because a companion voucher was used. I decided against filling in the form as we were only a few days away from departure so I booked a call back. Cancellation was taken care of quickly. The default is they will reinstate the voucher and put the balance in separate travel banks (one for each passenger). I asked to have the WJ$ reinstated and all the travel bank credits in my name. Agent was fine with that and I was told transfer from travel bank back to WJ$ would take a few weeks. I have since checked and everything is where it should be.

Suggest that if you stop for the night and the cell reception is good you call in and arrange for a call back.

HTH