Hi, I'm having problems with my MK7 Fiesta key fob and really need some help

It all started about 2 weeks ago when the key just died on a friday night, i thought it was just a dead battery and was going to pick one up on monday morning.
Sunday morning i woke up to find my girlfriend had put my jeans in the wash with the keys and a few other items inside, I dried out the key, replaced the battery and re-programed it to the car.

It was all working fine in till around Tuesday-Wednesday, now i have to press the buttons on the fob 2/3 times before it responds but in the end it does work

could this be because of the really cold weather we're having lately (snow Thrusday-Friday) or is it another battery.

I had the car serviced in fords last week and they said nothing.

Please Help!!!