"Terrible Service"

My mother is a diabetic 1 (unaware of hypos) she was brought into the Royal London Hospital for a hysterectomy in October, whilst operating they tore a hole in my mums bladder, they inserted a Catheter on the 27th Jan 16 and told it would be in for max 6 weeks its now the 25th May 16 and she still has this in, it has caused her a number of infections, she had an appointment for the operation to take place on the 30th May 16 but found out today (only because i called, my mother received no cancellation letter) that's now been cancelled and my mum has been put on another waiting list at a different hospital (Northwick Park, why i do not know), its disgusting service and i will be taking legal action if nothing is sorted before the 25th June, as i have spoken to a solicitor and he has informed me that by LAW 18 weeks is the max waiting time for a procedure