Hi Susana
It’s your work and you have every right to call it yours. In my opinion it’s actually fraudulent for somebody else to claim they made it when they did not. Just because this person buys something from you doesn’t mean they can claim it as their work.
It sounds very underhand to me, as Lou says I hope you haven’t been bullied! My advice is also to steer clear xx
Blossom Dream Cakes at www.facebook.com/blossomdreamcakes