I immigrated to the US last year but before leaving, I had a one-on-one discussion of my intention to apply to graduate school with the Dean and the HoD (individually), in order to get an affirmation that they would both write me letters when needed.
I have As in the courses and class projects that the Dean oversaw. On the other hand, I have Bs in the courses taught by the HoD but he acted as an informal mentor and panelled my thesis presentation, which I had an A in, so he is familiar with my competence in research.
Now that I've started my application process, when I reached out to the HoD, he immediately and enthusiastically agreed.
The Dean, however, was sceptical of my transition to another field instead of pursuing my undergrad field (I have a Bachelors degree in Economics and am applying for PhD in Organisational Behaviour). He advised me to apply for Economics in a list of schools he thinks are a good fit, and said that only then he would write me a letter. Which I personally think is ridiculous because my choice of program, especially one so closely related to economics, should not be a matter of concern to him. I tried to assure him that I would employ whatever I learned during undergrad and all he needed to do was vouch for my performance in research and competence the subjects he taught. I've had no response since. I would also like to add that one of the subjects he taught in is Econometrics, fundamental to research.
Now the deadline is looming ever closer and it's seeming more and more likely that I'll have to give up on the idea of getting a recommendation from the Dean.
Should I continue to pester the Dean, who might write me a biased letter, if at all, or should I go with the HoD's letter which will be fair but weaker due to my average performance in his classes? If I go with the HoD, how can I mask my grade to strengthen my letter (I am assisting in drafting the letter so I have some control over what to highlight)?