I went to Moscow and Leningrad in 1986. Just buying things - you queue to point at what you want and then you get a ticket. You take the ticket to a second queue, to pay for the item and get a receipt. You join a third queue with your receipt to collect the item.
I'd love to read more about that time, especially from people who lived there.
But as for receipts, we have this system till now at some stores, in car or computer parts stores, except that you write down item codes on a sheet of paper by yourself, or select them in a database, then you go to cashier to pay and get the receipt, and then you go and get the items from a guy that doesn't deal with money. Don't you have such buerocracy?
There were food supermarkets (универсамы) where you collected items into shopping carts and payed at the exit.
In 1986 there were just enormous queues and deficit of everything due to reasons out of scope for now...