OP, I think perhaps you don't understand how the GPs surgery felt. They knew you had an appointment, they were wondering if you'd be late, if they could squeeze you in.
Then you were 'no show, no call'.
You were on your way there anyway so you could have arrived late, explained about the traffic and apologised.
You could have called em route, it wouldn't have cost £5.
You could have called later when you got home.
You wasted their time. The traffic wasn't your fault, these things happen. But then you just ignored the fact you had an appointment.
Imagine you were meeting a friend at the soft play centre and you were late. Would you call? Or think, oh well it's too late no anyway, I'll just take DD to the park instead?
The GP staff are human beings, not robots. Treat them like that.