ONLINE PORTAL FOR KIDS SUCK

I am very frustrated with Spec-Savers, my daughter has been going there for the past 3 years as they offer the free for kids under 12 special. I had to make an appointment this year and was telephonically told I can only book online. Checked online only to see that the date I need to mark the 1 year after her previous appointment was not available yet (it only shows dates for a time period of 8 weeks and every day another day opens up), on the day that specific date opened, I checked in the morning at 07:00 only to find the whole day was already fully booked, I waited another day and again the following day was already fully booked. Phoned them again and they still couldn't help me with an appointment, even went in store and still couldn't help me make an appointment. I don't understand how it is possible for the days to be just suddenly fully booked when that specific day only opened today, I can understand if I wanted to book 2 weeks in advance, but I literally waited for that day to open online. I am taking my daughter elsewhere to do her eyes and they made my appointment over the phone without any trouble and even assisted me way before the 1 year lapse. Guess I am supporting them from now on.