If anybody can stop your pain over the loss of gardening vouchers (that you left on the floor), it's the boys in blue. I'm sure they will put every single resource into it and drop every other pointless case such as murders, drug dealing and car jacking until they have these vouchers (that you left on the floor).
Leaving it on the floor is a bit daft. I mean, if someone had just given you, say, £30 in cash you would not think "thanks for this cash, very generous, I will now put it on the floor for safe keeping" would you?