This past session, I informed the advisor of my previous issue and received an apology for the inconvenience, because while I was waiting for my point balance to be deducted after the refund, the advisor forgot to deduct it. I'm just glad I know what went down, finally. So if you've suffered this issue and are still waiting for your points to be deducted, don't. Try to get in touch with them and let them know that your points were never deducted (especially if you've already received your refund money).
As for the issue of the overcharged points on my own account, I'm assuming they'll just deduct those that are left rather than 'refund' the points that didn't get sapped by 'complete your set'. although I was only told my issue would have to be escalated, and that I'd receive an e-mail in 24-72 hours (I'm betting on Monday at the earliest). Furthermore, other simmers are having the same issue and brought to my attention the matter of mystery bag items. I didn't get one either (to my current knowledge), although I'm worried about pushing more than one issue at a time with the help chat, so as not to get too confusing.