In order to provide any useful assistance to OP, there are some additional details needed.
While OP says that this was a KL ticket, also need to know whether it was a KL-operated flight (not a codeshare, partner or anything else).
While it is in the past now for OP, this is a common issue on many carriers and, despite the view of some that one ought not to be required to do so, the following are helpful:
1. When a ticket is reissued, confirm that you hold a new e-ticket for the new route. Confirmations of resrvations are just that and do not have anything to do with tickets. That is an especially important distinction when the flight is not operated by KL.
2. If one is unable to check in online, that is an immediate cause for concern and should generate a telephone call. While there are many benign reasons for a failure of online check in, the lack of a ticket is one and that could have been remedied with a day to work on it.
3. Social media is fine for broad-based questions. But, it was not the route to take here and especially so when the response was not clear and precise.