Both following and violating a corruptly formed conscience can be wrong, but this dual wrongness does not dissolve the binding force of conscience on the agent.
Conscience in Aquinas’ view is not a special power or presence within us, but is our practical intelligence at work, primarily in the form of a stock of judgments about the reasonableness (rightness) or unreasonableness (wrongness) of kinds of action (kinds of option). Since each such judgment is of the form “[It is true that] action of the kind phi is always [or generally] wrong [or: is generally to be done, etc.]” or “phi is [always] [or: generally] required [or forbidden] by reason”, it must