I think you have given the radiator shop ample opportunity to excel....
I would go back with leaking radiator, get the money back, and go to their competitor and tell them what happened AND your expectations: right the first time (including the trans cooler parts).
Coincidently, this happened with the 300E about 6 months ago. The last time I walked in with the radiator, I didn't say anything. Nothing. I just looked at them with the radiator in hand. They knew, I knew. I got what I wanted. Oh, BTW, the radiator is just fine now.
My 2 cents,
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)