It's always better to have proper sockets installed, especially for bigger loads, but I don't see any issue at all with what you've done.
I did a periodic on a school a couple of years ago which had the exact same setup. We noted down as an observation that there were insufficient sockets in the classrooms, but in does not break any regs.
I did a periodic on a school a couple of years ago which had the exact same setup. We noted down as an observation that there were insufficient sockets in the classrooms, but in does not break any regs.