Be firm. Ask them to show you that the dents don't line up with the clamps on their repair stands. They should either be happy to oblige or they are less stellar than you think they are.
The good news is that seat tube dents are easier to straighten than dents in other tubes because you can drive the appropriately sized mandrel into the tube from the top while clamping the outside of the tube between blocks. There will be paint damage from all that movement (some cracking at the very least) and probably some residual small dents.
Brent
Last edited by obrentharris; 09-20-20 at 10:43 PM.
Reason: clarity