Does this sound like the buyer isn't happy or am I reading it wrong?

[HiccupHaddockHorrendous]

After receiving a neg on the weekend, I've had a positive fb from a different buyer who claimed the pic on the listing showed more parts. It didn't but I offered a refund. Buyer wanted to keep the item and I also offered them the part they needed at a much discounted rate. They declined my offer. They've now left a comment about how the extra part wasn't included eventhough it wasn't shown in the photo or listed in the description.

Received more fb today from a buyer which just says 'it is what it is'. Does that sound a bit crap or am I being sensitive?

I've been using eBay for a long time and sold a lot over the years. If anything, I under-sell my stuff and point out every little flaw. I'm just a bit fed up that i've had 3 iffy fb in a row

I wouldn't worry too much. You could leave a reply to the neg putting your side but make it very polite & professional and ignore odd feedback if they have left a positive. Some people do say odd things. They probably leave that feedback all the time - have a look at their feedback left for others to see. Don't get fed up, you will most likely get some good ones and the others will sink down your list and be rarely seen.