complaint

I gave in my mobile phone mid December for repairs under warranty as they say its still okey for to do so now today they are telling me that I have to pay for the repair because the screen was broken and not falling under warranty im waited about a month and that was not explained to me . I need my phone repaired and the supervisor is telling me that I must point the person who booked in my phone and I don't know them and it was more than 30 days that happen kindly assist Thank you