In our company one person from the team has to come to work on Saturday. We are a team of 4 so it comes to 1 Saturday per month (paid overtime).
Recently 2 guys left and have been replaced by other 2 guys who are unable to work on Saturdays due to religious restrictions. This means that the last month me and my old teammate had to work 2 Saturdays.
Our contract has no specific mention of Saturday, it just says something general about when the company needs overtime the employee is required etc.
How can I deal with the unfairness of this situation, where two of us are required to work on (now twice as many) Saturdays while the new guys aren't? Can I refuse to work on Saturdays too?