Don't be so sure about that. Elder discrimination is very real everywhere.
I'm 70 and I have experienced this at my local Lowe's and Home Depot on an almost regular basis. My age, (or yours for that matter), has nothing to do with it. Believe me. If you were in your 30's you would experience the same crap at these places.
These big box stores run like this all the time. (No help anywhere). Especially if you go there early in the morning. You could race a shifter kart up and down the isles, and not hit anyone. It is
ALWAYS self serve at my local Lowe's and Home Depot. And yes, I've even cut my own lumber. (They never lock out the switch at Lowe's.... Home Depot, sometimes).
I'm actually getting to be quite good at it. I know the store better than half the employees there. I'll grab one of those rolling stairs, move it to where I need, climb up to the top shelf, and start opening boxes. If an employee sees me up there, they'll immediately mobilize the store to get me what I need.
They're far more afraid of me doing a header, and end up with a liability lawsuit, than they are of helping you as a customer. So take a whack at plan B, and shame them into it. Works most every time for me.
Today you have to face the fact that customer service has gone to hell, and it's only going to get worse. Today the customer is not only never right, they don't even exist half the time...... Unless they trip over you.