I developed a medical device for my master's project. The general idea was initiated by my supervisor but the rest of the work is mine (Design, build up, test, measurements, results and some additional functions I added to the idea).
After finishing the master thesis my supervisor started to write a paper about my project. The information in the paper comes from my master thesis and it merely rewrites and summarizes ideas from my thesis. Additionally, all the results and discussions were also picked from it. I was away during this because I found a job in a different city. My supervisor then started to contact me and asked me to give him feedback about what he wrote and to explain the results and said that he would name me as the co-author. I was supporting until the point that I got very busy, but soon his questions become orders and he started to ask very silly questions so I stopped responding.
Finally, he threatened to acknowledge my contribution only, that is, to only mention my name in the acknowledgement and not as a co-author, because he was not satisfied with my support / me not responding to his requests for help with the paper.
The whole paper is taken from my thesis and all the results are mine on top of the added support that I gave but finally, he'll mention me in the acknowledgements only.
Is he right in doing this / allowed to do this and if not what can I do?
I am thinking of contacting the journal and explain all of this. What do you think?