Talking of ISP contracts, in France out ISP was Orange. If you moved house, you had to keep them as your ISP. When we moved to Anglesey, we told Orange of our change of address. We even went into the local shop and made them write it down, including Wales (in French).
Unsurprisingly, Orange could not provide a service but that did not stop them insisting on being paid for the rest of the contract. We didn’t and not only cancelled our DD, we closed the bank account to. That made them very cross and the letters got quite threatening, especially as they kept writing to the old address so it took a while for us to respond.
Eventually, we were visiting some friends in our old village so we dropped into the Orange shop to have a word and point out the small print in their contract that said the contract could be terminated early if they could not provide a service. It got quite acrimonious but Mrs N, who is fluent in French, stood her ground, by the time she had finished I felt quite sorry for the assistant. It was a side of her I have rarely seen.