Vodafone aren't allowed by any of the manufacturers to carry out warranty work is there's evidence of damage, which this would be. Your best bet is to go direct to Samsung as they will take a pragmatic view and allow themselves the flexibility to do the work free if they decide there's a fault. Micro usb sockets are quite fragile, so it's always advisable to connect and disconnect cables carefully. That said, there have been various issues with various makes over the years and manufacturers have often been sympathetic.
