Your pizza order needs no clarifications and if you get it wrong, it's just a pizza. If you misunderstand your mortgage you're looking at far more costly consequences.
Although you could well be right about the nature of the transaction, it's definitely a bad idea to be doing that with the bank!
If it's not the bank, and it's not you, it has to be someone else. You can ask over email for all the information available on the products from the bank and take it to an independent advisor. Eventually you'll run into the need to have a live chat with that trusted advisor or risk moving one mail per day in each direction trying to explain what you want and what you could get.
Maybe I'm in graduate school and my salary is called a 'stipend' and I don't get any payslips, plus I have a part-time job in sales where my base salary is very low and about 75% of my income is commission, and also my girlfriend will be helping with the mortgage, but not the deposit, and she's a Ukrainian refugee and self-employed content creator.
An expert who's seen it all before would know how to navigate my situation properly.
> That doesn't make any sense.
Tell me about it. They still won't give you a mortgage, though.
Why? I’d much rather have anything said in writing.