Sorry to hear OP is in the process of getting jerked with an incompetent dealer that clearly has no idea what they're doing.

You need some ebay keys, and the AK90 coder system. The 10 key limit is just not an issue anymore.

With the AK90, you remove the EWS module inside the drivers footwell panel.
Put the socket over the memory chip.
Load the app, delete all the old programmed keys. Use the tool to read and program your blank keys. You can even use it to read and program the quote 'dealer coded key' . You can get the programming plus get ebay keys for less than $150 all in.

I bought my E53 without any working keys, I made them myself.

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2003 4.6, esotril blue, over 215,000KM. Every previous owner failed to keep up the vehicle maintenance. Restoration project.