Copper plated saucepans

[StressedTired]

I bought a set of copper saucepans at Christmas. After only three months, they look awful! Even though I wash up afterwards they look stained. Like, one day cooking pasta it bubbled over, dripping down the outside of the pan, a couple of months later the outside is still stained despite many washes since. All four pans are stained. I've tried normal washing up liquid, white vinegar, lemon juice, a soft coconut hair pad, nothing gets them looking clean and shiny again. What have I done wrong? How can I make them look nice again? They were not cheap... And I've had them too long to return.

Re the title, I'm actually not sure if they are copper pans or copper plated, but it's the copper on the outside that's the problem so possibly they are a different metal inside (which still looks fine and sparkling clean).

With my copper pans I ( occasionally as am lazy) get them to the sink then sprinkle lemon juice over the copper then add table salt, wipe with an ordinary dish scourer and they come up as almost new

Same here OP. Got a copper frying pan that was lovely the first few times. Looks awful now and no better than any other pan.

Bar keepers friend, the powder stuff, works amazingly well