A space with stable WiFi that is open on Sunday morning?

Hi lovelies, could anyone help a tourist out? I'll be in Croydon on June 14th. I will need stable WiFi and an outlet for a call between 10 am and 2pm (yes 4 hours), and I realized that after booking my stay with a Sunday 10am checkout. Any public place that is not too loud but also does not have a problem if I talk? (libraries are therefore out, not that I suspect any to be open on a Sunday) i dont expect it to be free, but depending on the price I might just decide to book for another night instead 🥲