1996 c220

My remote to open and lock the doors will not work because the batteries in the remote get sucked dry within two days. I have changed them with new ones multiple times and within two days they stop working. I check the batteries and they are both dead.

So something is draining my remote batteries. The remote is not stuck on and it is not transmitting so I have no idea what is draining the batteries.

Any ideas and is it possible to buy a new remote?

Thanks.