Blacklist a lost phone

[FinOD]

Hello I lost my phone last week and my 3rd party insurance company is asking for the lost phone's IMEI number to be blacklisted for the claim to be processed.
I have asked O2 to blacklist the phone and they have barred/blocked the phone.
The insurance company say that this is not blacklisting.
O2 customer services say that this is all they can do.
The insurance company will not accept this and insist it can be blacklisted.
I have tried on numerous occasions and phone calls to no avail.
Please can someone tell me how I can get the list phone blacklisted so that I can get my claim processed.

[MI5]

@FinOD 

Blacklisted / Barred / Blocked is all the same thing.

Your insurance company is stalling.

You can check for yourself here https://www.imei.info/

[FinOD]

This is the problem as the lost phone's IMEI number is not showing up as blacklisted on this database even though O2 blocked/barred the phone on the 12th!

[MI5]

It may not show instantly @FinOD 

It depends how often the database is updated.

You could ask O2 for a letter to give to your insurance to prove they've barred it.

[FinOD]

Have already done that and the insurers won't accept it unless it appears as blacklisted on the database

[MI5]

I guess it's just a case of waiting for the database to be updated then.
It's one of the downsides of not using the networks own insurance.