"you can't afford to be ill"

I've just had Major Neck Surgery at The Royal Derby Hospital, they were great. When I was discharged they gave me a sick note for 3 weeks off work. On the sick note it said, I encourage Mr Neville to see his GP if further time off work is required to recover. This information was also sent to the Surgery. So on the Monday before my Sicknote ran out on the Wednesday I tried to ring the Surgery - spent over 2 hours trying to get through and couldn't. So I rang in the afternoon and got through after about 10 minutes to be told I would need an appointment with a Doctor and would have to ring back in the morning, this is the way it is. I tried ringing the next day at 8.15, finally got through at 8.50 to be told no appointments left! After explaining my situation to the receptionist she said, I will see if I can get the Doctor to do you a Sicknote as it's just an extention to the one you,ve got. So I said when can I pick it up and was told to ring again after 11 on Thursday. I rang on Thursday ,and guess what, no Sicknote and the Doctors off today! You'll have to ring Friday after 11 again. What a shambles. You can't afford to be ill can you. Can you tell me why it is so much trouble to get something as simple as a Sicknote when the Surgery is aware of my situation? This is simply not good enough. I dread the day I need help from this Surgery again.