Is calling in the same as calling in sick?
I called in sick once (an HR before my shift as per the handbook) and still got a write-up. I now have 100+ sick hours and I'm afraid to use them.
Yet I see some call in or call in sick once a month and get away with it
Generally I think they play favorites. OP, They just hate you.
Are you generally on time and do decent work? Are you full of excuses about why you can't make it to work once or twice a month?