Keys not handed over on completion

We received a bundle of keys from Estate Agency after completion. None of the keys were identified by labels. We expected to receive a key for freehold flat and three keys for the leasehold garages which form flying freehold, clearly identified. 

We arranged to meet garage leaseholders to introduce ourselves and also inspect the garages. On opening the garage by leaseholder, (the key used to open the garage bore no resemblance to any on the bundle.), one of the leaseholders was surprised to see pipe work had been installed without their knowledge. So we presume, previous owner had accessed the garage.

The previous owner was insistent that the keys were in the bunch.

Why then, did he not identify just the three required? It seems strange that we were handed a bunch of unidentifiable miscellaneous keys.

Are we entitled to receive keys to the leasehold garages, being landlords as we were told by the Estate agency? The flat has a tenant. Should there be a further leak in the future, we need to fix immediately for the flat tenant and protect contents and building. The garage leaseholders live outside the town and so might not be able to open the garage in an emergency. In that case, should we access the garage after notifying leaseholders and do not receive response immediately?

If we are entitled to receive keys, what should we do next?

Many thanks

Zora