Right, Just Blame Me

When people ask you to do a favour for them isn't it natural for you to do things at your own time and at your convenience? My mom wanted me to change her appointment date as she complains that she has to go to the hospital every week for 3 weeks as she has to see 3 different doctors. What I don't understand is why she did not change the date at the point when the she was given the appointment dates. She should know that 3 different dates were given to her and if she does not want to go down to the hospital on 3 different days, she should have mentioned to the clerk at the point when she was given the 3rd appointment date.

Now she wants me to change her appointment date obviously I can only do it when I am free. When she found out that I have not changed the appointment date, she became mad and said she'll do it herself if I'm not willing to do it for her. I'm working at the front line in a general hospital, I can't just walk off to the clinic to change appointment dates as and when I like it, and it does not make sense at all for me to walk to the clinic when I can just pick up the phone and make a call. Unfortunately, things have been busy at the pharmacy, and when I do have time to call, the clinic line is always engaged. Feeling really pissed off that she's not understanding at all. Can't even have peace when I return home...