Yes, you can still buy Return tickets.
On journeys where pay as you go with contactless is available, Single tickets now cost around half the price of a Return ticket, whether you pay as you go or buy a ticket for your journey. It may be cheaper to buy 2 Single tickets or pay as you go with contactless rather than buying a Return ticket, on journeys where pay as you go with contactless is available.
For example, if you make a peak journey in one direction and an off-peak journey in the other, then an Anytime Day Single plus an Off-Peak Day Single will be cheaper than an Anytime Day Return.
When you pay as you go with contactless, you will be charged the best adult fare for your journey on the day and time of your travel.