got scammed on tt

I saw this mini saintifik cushion that's like a keychain on tt so I purchased it but what came was a mirror , for context I paid with debit and when I asked the seller for a refund because the cushion was rm 16.00 with some other things I bought from them, they refused and just blocked my account the thing is, I dont know how to report it to tt because it's too confusing. can someone atleast tell me how?