False Promises / takes too long to reply

Can someone please give proper feedback as to why Medshield would not adhere to promises made in writing We were part of Medshield and moved over to Discovery to get some benefits that Medshield did not cover. The plan was always to revert back to medshield. Medshield confirmed telephonically (please pull recording) as well as on email in writing that once we return there will be NO WAITING period. We wanted to rejoin for Start of 2016 but now apparently the email is not enough and there will be a waiting period? How is this possible?? My reference number is: 201115QJ845K, feel free to contact me for any proof on email as well. Email replies to the issue takes more than 3 days and at this stage we need some answers urgently as I still believe this is unacceptable.