iphone wifi/icloud issue?

I bought an Iphone 4s for my partner from Amazon but the wifi was broken after just 2 days and did not turn on. I tried to format the iphone but it would not let me do it as it told me I had to turn off find my iphone. However I could not do this as the internet on the phone does not work. Therefore I put it in recovery mode then fomatted it. After this it displayed the welcome/hola message for set up. In this instance my data etc would have been all wiped from the phone, is this correct?

The reason I ask is that the seller has told me I have icloud locked the phone and will not refund me. I don't know if he is being honest or just trying it on because he has already made many excuses not to refund me (gave me a fake return address, then tried to say it never arrived despite having signed for it, then admitted he did have it back but said he had to wait for the guy who deals with returns to be in to process the refund, now its this icloud excuse). I don't understand how I can icloud lock it with the internet not working, or how I am expected to 'unlock' it being that the seller has the phone now. Is it really possible to lock a phone to icloud like this ?

Thank you