First, you need to be coached. A TL or etl will talk to you about being late. Usually, this will happen 2 or 3 times. If there is no improvement, you will be given a CCA. This is something that you have to sign. If there is still no improvement, you will be put on a final warning. This step lasts for a year.
If you get a CCA for the call in, I would ask when you were coached. They should be able to give the exact dates. You should be told that you are being coached when it happens. If this is not how it happened, go to HR. The Bullseye likes to cross t's and dot i's.