The council says its booking trial is working. My only booking failed. What should I ask?

The presentation called the new bulky-waste booking trial "a promising success." I was looking at the cancellation message from the only collection I'd booked.

I couldn't finish the booking online and used the phone number instead. A slot was arranged, then cancelled before collection. My neighbour used the same trial and says hers worked smoothly. I don't think either of us can describe everyone's experience from one booking.

The councillor leading the discussion asked for constructive feedback. A friend wants me to say the whole system has failed; another says I should stay quiet because teething problems are expected. Neither quite matches the question I have.

I'd like to know what the trial was meant to improve and whether a booking counts as successful when a slot is created or only when the collection happens. How do I raise my failed booking alongside that evaluation question without presenting my experience as the whole verdict?