Returning a phone to Costco

Has anyone returned a phone to Costco? I switched from a Huaweii to a Samsung A52 at Costco and had to switch providers fro. Public Mobile to Virgin Mobile. I am considering buying the OnePlus 8T since its on sale and feel that it would be a better phone but Costco doesn't sell the OnePlus phones.

I am curious to know what the process would be like if I returned it. I would assume since I have signed a contract with Virgin I may be stuck? Costco has a 90 day return policy? Or would I be able to switch phones providing its a phone that is with Virgin?