cmh

You just need to have a look on your bills. On the backside, you have black on white all the clauses that are part of your contract.
If you don't want to break your contract, you can simply transfer the meters to the next tenants/owners.
As customer, you have a dedicated zone on their website where you can proceed with the transfer of your meters.

By doing so, you don't have to pay any penalty for breaking your contract earlier.