When doing a whois check on your IPs allocated to you from Route48 you may find the whois data comes back to Route48.

This is because the prefix doesnt have an ORG tag so ripe is reading the ORG tag from the parent prefix from which yours has been assigned from.

The following tutorial expects you to know what ORG & MAINTAINER objects are and how they are used on RIPE.

The first thing you need to do is go to your ORG object in the RIPE DB whilst logged into the account attached to it, if you have a "Sponsored" ASN then you will probably have a "mnt-ref" with the sponsoring Maintainer role in and a "mnt-by" with your own maintainer object name in, you will need this in a moment.
You will then want to click update object and add a "mnt-ref" with your maintainer object in. 

You will now need to go to the prefix assigned to you by Route48 and add the ORG object you just updated.

Once that has been updated the prefix should now show up in "My Resources" with in your RIPE account.

Now when you do a lookup on your prefix you will see yourself as the responsible organisation and the correct abuse contact will then be listed