So I called MM and explained what happened. They want me to return the sets (including a used one, ew) and they will send me new ones. Or rather, they sent me one box of new ones and envelopes and canisters to return the old ones. Once they receive those, they will send me the other three boxes. I can understand it, but it doesn't entirely alleviate my panic at only having half a box of sets. Anyway, I sent the old ones back but I don't know how long they'll take to arrive at MM.
Now MM has been dinged for their customer service (even by me). One problem that I see became clear after talking to the same person in sales and supplies more than a few times. It seems that the sales people are not trained on the products they're selling. I learned that this person had never seen a data cable and didn't really know how infusion sets worked. I am a lot more clear on how I was mistakenly sent IV-3000 instead of IV Prep - they're just words on a computer screen to someone who doesn't know what they are. If people call up and don't know the name of what they want, they have to talk to the Helpline.
Last time I had to order tubing (from the Sils), they tried to talk me out of it because I'd just ordered sets (Sure-Ts). When I finally convinced them that yes, I wanted to buy more sets because I only needed the tubing, they tried to get me to order the box with 5 sets of tubing and 10 cannulas for $100, instead of the box with 10 sets of tubing and 10 cannulas for $116. It took 5 minutes to get them to understand why this wouldn't work (during which they kept trying to get me to talk to the Helpline). I think the major issue is that we might as well be talking about floobles and gargs for all they know. I think it's a problem when people don't know what they're selling. I know they can't give out medical advice, but they should at least know what people are talking about when they say they want to buy something. If they solved that, they might solve a lot of the complaints.