@Andy ********
, Your TM30 record is still valid. As your TM30 receipt has already been submitted, and you have proof of the same address (yellow book) that might be why they didn't ask you for a receipt.
Still, there could be a possibility of being asked for a receipt.
In that case, tell them you don't have a copy, no changes since registering. They just let it go or tell you to get one. If you are directed to get a receipt, go to the TM30 counter for that. As you bring your yellow book, it's not difficult to re-submit or get a receipt there.