Getting annoyed with trade requests for my collection that's not for trade

I’m getting really frustrated with people who keep asking to trade my special pet collection even though I’ve made it clear they’re not available. I have this awesome collection of mechanical pets that I absolutely love and I’m super proud of them. Yeah I only have 4 of them but they mean a lot to me so I keep them locked. I even mention in my profile that this collection is special and not for trading. But people still come up to me asking for trades. Just yesterday I was hanging out with my friend doing some grinding when they went away from keyboard for a bit. This random player walks up and wants to trade all my mechanical pets for just one dinosaur. I politely explained that my collection isn’t for trade but they got upset and started arguing about how their offer was supposedly fair. I told them I wouldn’t trade even for the most valuable pets in the game because I genuinely don’t care about rare items. They called me selfish so I suggested they work on their attitude. I don’t usually get into arguments but I won’t let people be rude to me either. Maybe they should learn some basic politeness before approaching other players.