tracker has me by the bits

Tracker has me by the *****..

So bought a second hand car (with a tracker directly fitted on the battery, for "'data only, per sources"')

Tracker does not want to remove it, or "'threatens" indirectly, to "flag" my car should i remove it myself (per there agent acting on their behalf) . Strange, as I have a letter from the previous owner and the car is registered in my name...so essentially, tracker unit on my battery, is *******ly riding un my car.

The "real reason" is the, previous owners contract still fresh, and they want me to take over the contract.