I am in my 60's and haven't had any problem to date.
When I contact a new lady I always ask "Do you see guys in their 60's, or do you only see guys closer to your own age?"
Generally the comment has been something along the lines of I prefer men in their 50's or 60's as young guys can be hard going and the older men usually know exactly what they want, are they more courteous and treat me well.
So personally, hasn't happened to me but if I was quoted extra I would just go to one of the many ladies who are happy to run their business and their price is their price (which I never try to negotiate) and I am happy to pay them in full.
Sorry to hear about your difficulty but there are many other ladies out there.
Smetner