"Terrible nonexistent service"

My mum was referred to them by her GP and they booked a telephone appointment on 13th December morning and no one called her at all. We then made phone called on 16th and 17th to the centre and no one answered my call despite I was sitting as No.1 of the queue for over 15 minutes each time. I appreciate they might be busy, but they should give an explanation of why no one called at least. Looking at the good reviews of this place, staff are extremely rude towards patients as well. Should this service be funded by the NHS even though they have done nothing good for the society?