In my work we do a roster share if you work part time.
Someone works the 1st two weeks and someone the last two weeks of the month.

At my back to work interview I had told my boss i wanted to work the 1st two weeks of the month but was told no as the person who i would be sharing with wanted the 1st two weeks, i accepted this quietly but wondered how the decision was made (if in a fair manner then i dont mind, i should point out though the other person is friends with our boss)

I have just found out though the other girl due back just had her back to work interview today so why on earth was she given exactly what she wanted over me??

Is this legal to do it in this manner?

Have I been screwed over?

I work in the UK airline business.

Any advice appreciated.