What time is it? Watches and horology

Got it evaluated and he says it's got a different strap (and not worth what I paid for it) that's from different older watch. If it says it's mint on ebay, can I dispute it and get my money back? Anyone got advice please help.

Open a dispute on ebay, this starts by you sending an email to the seller with your worries/demands. If they can't satisfy you* then you can report it to ebay and they'll step in. If the description was wrong, then you have a pretty strong argument. I got my money back immediately when I escalated it to ebay, but that was only £6.
Good luck!

*ifyouknowwhatimean