Bad service from Telkom

I received a phone call from Telkom to upgrade my landline to a faster service, unlimitedhome 4 mbps, and I agree. On 24 May 2018 I opened my e-mail normally, and everything was fine. During that morning they migrated my landline to the new service and after that all my e-mails and folders disappeared. I phoned 10210 numerous times and some said it could be retrieved and other said no it cannot be done. On Sunday at 15:33 I received a sms with ref no ********** 5, phoned Monday morning on which they told me the call has been closed. I did send a mail to their abuse line but no response on that. I am not satisfied with this as all my information is gone.