My colleagues all gained promotions whilst I was on maternity

There was a restructure at my organisation whilst I was on maternity leave. There were several of us in the same role. As I was on maternity leave, I was ‘job matched’ to another role at the same grade whilst my colleagues had the opportunity to apply for a range of positions and all gained promotions. I wasn’t allowed to apply for any of the other vacancies and 2 years on my ex colleagues now earn nearly 10k more than me.