I would appreciate some advice with respect to my situation.
I was offered a job in Austria (I'm from the UK) back in the summer of 2019. The job was conditional on finishing my Masters Degree in the UK, which I was set to do in September 2019. I was set to start 1st of October 2019. I moved over and began working. However, when there, I was told that I would not be given a contract (and hence paid) until they had confirmation not only of finishing my masters but that my final grade would be a pass (or higher). I was told on the 3rd of October that, when I had this final confirmation of grade, my contract would be backdated to the first of October and I would get pack-pay. I have this in writing in an email from the HR department. I accepted this offer and continued turning up to work, expecting to get back pay.
In December 2019, I got the final confirmation from my masters course (including confirmation that the date of completion was in September, before my start date). The documentation was sent to HR but they have now refused to backdate to October, stating that they only backdate to when they receive the documentation, not, as had previously been stated, to when I was told to start.
I've been working for three months at this institution on the information that I would get back pay for this.
Given that they told me I would get back pay and I worked conditional on that information, am I entitled to it?
Thank you all in advance.