Some background info. I work for a company where I can mostly work from home but I occasionally have to go out to meet clients and perform audits. My company pays for my monthly bus/train pass.

My mom is very frugal (see also: cheap as fuck), and uses my pass on the weekends when I don't go out. This has been fine for the past 4 years, until she retired earlier this year. Now, every day she asks me if I am going out for work, and if I'm not, she will take my pass. HOWEVER, on days that I do go out for work, she will fucking call me in the middle of my schedule to ask me when I am coming back so she can use the pass. I've told her to stop being such a cheap-ass and just use her own money instead of waiting on me to save a few bucks. She firmly believes that there is no reason to spend money if there is a chance not to, even if it means pestering me with constant phone calls (3 calls in 1.5 hours just today asking when I am coming back). This has been happening for months. The phone calls are an extra annoyance built up by years and years of her calls just wasting my time with stupid shit.

I am planning on telling her that if she calls me again and interrupts my day with nonsense like this, I won't ever pick up her calls even if she is in an emergency, and I will never let her use my pass again. Is this too much? Is there a better way to get her to respect my time? My Canto is shit and her English is shit. I don't know how to get my feelings across without swearing in English and then just saying "forget it" when I can't explain something to her.