You are not the only one experiencing this. You can search in this forum on many many stories and suggestions how to stop / ban this services on your mobile. Since u have received the SMS responce and they have a contact point / URL, try to go to the site or call to unsubs. I know, its pretty troublesome.
The shortcut is - report directly to MCMC / CFM since this has yet to resolve after ur complain to Celcom. I hope u have the report number when you reported to Celcom to stop the subscription. You need to quote that to MCMC. Me and fellow members of this forum have been giving many ideas and voiceing out our concern. But I guess, nothing has been done so far that I know. So, the best is to escalate this to the authorities. These 'parasites' r sucking every credit / bill while they can. You can stop them by doing this. All the best!