just opened my Medela swing to remove the batteries and horrified to find mould growing all over and around the black sponge inside the battery compartment! And a horrible sour milk smell to boot. This happened to anyone else? Is the pump a write off? I plan to contact Medela but interested to hear about others' experiences. I've followed the cleaning instructions for when milk gets into the motor and wiped off the mould but not sure whether it's even possible to clean the sponge. Thanks