I was told today my 1997 Mercedes E420 is locked in theft mode and the engine cranks but will not start

What is your question?

Recently changed my battery, since then, will not start. First repair shop had it for almost 2 months, gave up, I took the car to another shop, they told me it was locked in theft mode, thanks to changing the battery. Short of going to the Mercedes dealership and giving them more than the value of the car, is there any other way to get the car out of theft mode?

What makes this problem better or worse?

Cold, hot, no dif.

How long has your 1997 Mercedes-Benz E420 had this problem?

Since Easter