Welcome to this user forum. @Amzlod
This is a BT Retail forum for BT Retail customers, and cannot help with number porting between other providers. BT only has control over number ranges that are owned by BT Retail, so unless your number was originally issued by BT Retail, there is nobody on this forum that can help.
Each provider has their own number ranges.
You would have to take up the issue with Sky or Virgin media.
Was it Sky who first gave you your phone number?
Thank you for your quick reply.
It was a BT number first of all.
Sky and VM seem to be unable to help, even though it was their fault that it got lost in the first place.
The number rings, but nothing happens, and it has been like this since the transfer happened.
Then the number would have reverted back to BT Retail, which is probably why the number port failed as you cannot port it out twice.
Are you still living at the same address that you were, when BT Retail first issued your number?
If you want to check to see who actually owns your phone number, then
If you have a quick look at the OFCOM website :-
and download the spreadsheet that contains your number range (note the numbers exclude the leading zero). The line in the spreadsheet will show to whom the range is allocated.
You can then see if it is BT Retail who owns your number.
If you are living at the same address, then your number will exist on the local BT exchange.
There should normally be no problem getting your number back if you transfer your phone service to BT Retail. Not sure what you want to do about Virgin Media, that is something you will have to deal with.
You would initially be given a new number, but once it is active, you can request a renumber back to your original number. At that point you may need help from one of the forum moderators who will read this thread and help you to get your number back.
Its never 100% guaranteed, however in most cases there is no problem.