Regarding returns, according to their T&C, the credit will be applied to the original form of payment. Hence, buying & paying with cc will result in a cc credit and likely clawback. Having store credit applied may be worth asking for, but I would think it is down to their discretion.

I guess, I'll buy a $100 GC from now on and let my +1 spend it with her cc's credit.

But these cutbacks (e.g., airline fee credits) are starting to p*** me off.