Booking platform that older patients actually couldn't use — back to square one

we trialled a couple of booking platforms over the past year. one of them had such a clunky interface that patients over about 55 just couldn't get on with it. we ended up getting more confused calls coming in than before we started using it. not ideal. does anyone know of a booking tool with a genuinely simple patient-facing interface that doesn't assume everyone is tech-comfortable?