Once a contract has been terminated via the customer panel and the termination has been revoked it cannot be reversed. The only crucial factor regarding a termination is the current state of the contract which can be reviewed in the customer panel (menu entry "Contracts / Orders"). A contract which has been terminated is marked with a red flag. An active (i.e. not terminated) contract has a green tick in the "State" column.
Information on how to terminate a contract can be found under the following link: