Sorry to query this, but do you mean a seller had your number?
Sellers are always given your phone number when you buy an item.
If it was a buyer, then come back and confirm this and you can be told how to stop your number being given to buyers.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)