Delbhoy

Hi all I've a mk3 finder and was working great till the other day when I was changing the batteries in both the collar and box when changing the batteries in the collar I sat them on the counter and accidentally put the box down on them and they stuck to the bottom of the box where the magnetic bit is to turn the collar on and off since then it's not turning the collar on then when I manage to get it on it won't turn it off anyone had this issue before