Suggest I Commit *****

Last week i took my Sony Experia Z3 in for repairs however when the Agent checked my phone they could not find the IMEI number on the phone and suggested that i rather report the phone ****** as the Tech team would not accept the Phone without the IMEI number visible. My phone does not open as it is a sealed phone so how can they see the IMEI number? Also I pay insurance every month so that if my phone breaks they can fix it and the IMEI number is attached to my sim so why can’t they just pull it from there to verify that the phone I have had for 2 years is the one I am having repaired. Lastly why would an agent advise me to rather report the phone ******??? That is *****!!!!