How do I unlock an iphone se

Hi- I have a refurbished iphone se 2020 I purchased last week from Best Buy. I did not finish setting it up when I should have when I purchased it. I did put a mint sims card in it. It then started asking me for my passcode. I do not remember entering in a passcode. I entered in the only one I could possible use, and it was apparently the wrong one. Now my 7 day free Mint trial is over, and my phone is locked. I tried signing up for itune and connecting it to my computer, but nothing comes up on my itunes account because my phone is locked. Mint says I need to find out from Apple how to unlock my phone, and they tried connecting me to apple support, but after 3o minutes on hold, I told her to give up. Any suggestions without going to the Apple store, and paying lots of money?