SeaDoc
2018 P3 on FSD Beta & 2022 X Plaid FSD
According to OP Tesla agreed to the July delivery two weeks ago. It is only after the fact that they are imposing new costs on it.
I can't imagine that an extension was made without any written documentation provided about the risks inherent in such an extension. If Tesla clearly did not have anything in writing regarding this extension, the OP has the right to fight it. In the initial purchase/order agreement, there has to be something to protect Tesla regarding the extension/postponement of any delivery. Ask the Sales manager to show you - otherwise get him to pursue to Corporate to honor the original agreement.