Bra Genie tells me I'm a 28F/30DDD, but tells me my 32D bra is way too big for me?

Went to get fitted today, all of my bras are different sizes (32D, 32B, 34C) but they all fit pretty well. I wanted to get measured to have a definitive size bc I wanted to go shopping for new bras.

My under bust is 27.5 inches and my bust is 32 IIRC. The lady told me I was a 30DDD, 28F, or 30F. She hands me a 30F to try on and the cup is WAYYY too big. Gapping at the top, underwire is too low on my rib cage.

She tells me it's a perfect fit! I just left and told her I'd think about buying the bra she tried to sell me ($84) and come back later, but honestly that seemed so incorrect.

The sizing seems so wrong. Visually, I was thinking my boobs were likely around a C. I wouldn't place myself as having a particularly large chest.