Wow, sorry to hear about that. Very frustrating.

During a head gasket change, a good shop will check the flatness of the block and the head, and adjust them as needed. I think the block may have to be machined outside of the car, but others can weigh in on that. All of this is an opportunity for a shop to make more money, so it would seem odd that a shop would skip these steps. If it isn't itemized on your bill, I would just ask them what specifically they did. If they didn't do something, they should be able to explain why. Good luck!

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1968 220D, w115, /8, OM615, Automatic transmission.
My 1987 300TD wagon was sold and my 2003 W210 E320 wagon was totaled (sheds tear).