Overpayment To SFs, Using Credit Balance

An item I mail ordered from SFS aka The Cave was unavailable. Though I checked the "allow Forever stamp substitutions" box, SFS sent no alternate for the item. The invoice report shows my overpayment but no notation of a credit balance. About the missing item the report states "please reorder".

So upon my next order will SFS automatically remember and know to apply the credit balance? Or do I need to include special instructions? What's the best way to handle it?

FWIW, when similar has happened in the past and I did NOT check "allow Forever stamp substitutions" they've sent other items in place of those unavailable, which seems backward. Am I misunderstanding how the substitution checkbox works?

Best way to find out is to call the cave, since they are the ones involed,

Peter

My experiences with 'the Cave' is that if your order is not completely filled because of item not available & remainder of order is filled & shipped, they will issue a check for the outstanding credit balance soon after. They do not maintain a credit balance (except for standing orders for certain items) At least in my experiences over the past 15+ years.