I think that you feel enough doubt to warrant looking at the Ink bag seriously even if you have to pay to send it back. If you haven't taken the labels off the Oak bag and used it yet, that may be because you are really worried by something about it.
Oh what a feeling ! I think it is always better to see for yourself what you like the best. After you made your decision you will know for sure (hopefully) that you made the right decision. And you don't have to reiterate, did I pick the right one or not ! look forward to hear what it will be !
If you think it's worth spending on the shipping charges to be sure you got the right bag, then go ahead with the order. I personally would do that - to be satisfied that I got THE bag, or I'd always be wondering. The fact that you even ordered the Ink suggests you need to know? Good luck!